UBC Wiki - User contributions [en]

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T23:19:44Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

=Music with Huge Reverb Times=

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of a huge reverb sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Fig. 2: Time x Amplitude Graph of a sound with long reverb tail. Source: Own work]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Jonathan. "Space within Space: Artificial Reverb and the Detachable Echo." Grey Room, vol. 60, no. 60, 2015, pp. 110-131, doi:10.1162/GREY_a_00177. </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Fig. 3: Time x Amplitude graph of a bath house's space signature, generated with Waves IR-1 from their IR library Source: Own work.]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Fig. 4: Time x Amplitude graph of an Impulse Response of a Russian Synagogue, generated with Waves IR-1 from their IR library. Source: Own Work ]]

===How Sounds Behave with in Environments with Huge Reverb Times===

In music with huge reverb times, percussive sounds — drums, wood blocks and tambourines, etc -- are often foregone. reflections from repeated percussive sounds in highly reverberant spaces cause a buildup of sound waves within the space. This situation usually results in a kind of sonic mush, which is why music composed for environments with no reverberation (smaller spaces, outdoors) tends to be more rhythmically focused and complex<ref>Byrne, David, and Ebooks Corporation. How Music Works. McSweeneys, San Francisco [Calif.], 2012.</ref>

As a condition of the environments available to them, composers of music with huge reverb times tend to use mostly sustained sounds that will be supported by the reverberation of the space. Sustained sounds, such as the sound of organs or bowed instruments, function differently because they feed energy into the space for the duration of the sustain, until, for example, the violin player stops bowing. This results in a buildup of sound energy until the input rate equals the absorption rate, and then the decay of the reverb. Reverb will build up on top of the source sound as the source excites the modes of the large space or electronic device. A common example of music composed for huge reverb times is music for the pipe organ, which is often supported/ inhibited by the 2 or more second reverberation of a church or cathedral.

===An Example: Deep Listening Band===

The Deep Listening Band, an experimental project of David Gamper, Pauline Oliveros, Stuart Dempster, recorded in the Dan Harpole Cistern, a structure at Fort Worden Park in Washington State. The empty cistern, which at one time held 2 million gallons of water, is 200 feet in diameter and 14 feet deep, giving the environment a truly huge reverberation time of 45 seconds.The music the trio composed there was consisted entirely of long, sustained notes, as percussion instruments would not be discernable in the "uniform acoustic" of the space. Dempster says of the experience: “playing in the cistern teaches two things to a musician: one is having a secure tonal center, and the other is intonation. If the attack is unstable, the reverberation captures all of that instability. If intonation is not accurate, the cistern lets one know... When one stops a mistake in a normal playing environment, the mistake has the decency to stop—not so with the cistern!” <ref>Evans, Nat. "THE CISTERN CHAPEL: RESONANCE FROM THE PACIFIC NORTHWEST." ''New Music Box''; 2016. url: http://www.newmusicbox.org/articles/cistern-chapel/</ref>

===See Also===

*[[Reverberation]]
*[[Deep Listening Band]]
*[[Room modes]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T22:30:42Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

=Music with Huge Reverb Times=

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of a huge reverb sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Fig. 2: Time x Amplitude Graph of a sound with long reverb tail. Source: Own work]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Fig. 3: Time x Amplitude graph of a bath house's space signature, generated with Waves IR-1 from their IR library Source: Own work.]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Fig. 4: Time x Amplitude graph of an Impulse Response of a Russian Synagogue, generated with Waves IR-1 from their IR library. Source: Own Work ]]

===How Sounds Behave with in Environments with Huge Reverb Times===

Percussive Sounds

Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once. In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref>

As a condition of the environments available to them, composers of music with huge reverb times tend to use mostly sustained sounds that will be supported by the reverberation of the space. Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space.

===An Example: Deep Listening Band===

The Deep Listening Band, an experimental project of David Gamper, Pauline Oliveros, Stuart Dempster, recorded in the Dan Harpole Cistern, a structure at Fort Worden Park in Washington State. The empty cistern, which at one time held 2 million gallons of water, is 200 feet in diameter and 14 feet deep, giving the environment a truly huge reverberation time of 45 seconds.The music the trio composed there was consisted entirely of long, sustained notes, as percussion instruments would not be discernable in the "uniform acoustic" of the space. Dempster says of the experience: “playing in the cistern teaches two things to a musician: one is having a secure tonal center, and the other is intonation. If the attack is unstable, the reverberation captures all of that instability. If intonation is not accurate, the cistern lets one know... When one stops a mistake in a normal playing environment, the mistake has the decency to stop—not so with the cistern!” <ref>Evans, Nat. "THE CISTERN CHAPEL: RESONANCE FROM THE PACIFIC NORTHWEST." ''New Music Box''; 2016. url: http://www.newmusicbox.org/articles/cistern-chapel/</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

===See Also===

*[[Reverberation]]
*[[Deep Listening Band]]
*[[Room modes]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T22:11:10Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

=Music with Huge Reverb Times=

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of a huge reverb sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Fig. 2: Time x Amplitude Graph of a sound with long reverb tail. Source: Own work]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Fig. 3: Time x Amplitude graph of a bath house's space signature, generated with Waves IR-1 from their IR library Source: Own work.]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Fig. 4: Time x Amplitude graph of an Impulse Response of a Russian Synagogue, generated with Waves IR-1 from their IR library. Source: Own Work ]]

===How Sounds Behave with in Environments with Huge Reverb Times===

Percussive Sounds

Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once. In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref>

As a condition of the environments available to them, composers of music with huge reverb times tend to use mostly sustained sounds that will be supported by the reverberation of the space. Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space.

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

===See Also===

*[[Reverberation]]
*[[Deep Listening Band]]
*[[Room modes]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T22:10:07Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

{{Infobox_Music with Huge Reverb Times}}

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of a huge reverb sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Fig. 2: Time x Amplitude Graph of a sound with long reverb tail. Source: Own work]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Fig. 3: Time x Amplitude graph of a bath house's space signature, generated with Waves IR-1 from their IR library Source: Own work.]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Fig. 4: Time x Amplitude graph of an Impulse Response of a Russian Synagogue, generated with Waves IR-1 from their IR library. Source: Own Work ]]

===How Sounds Behave with in Environments with Huge Reverb Times===

Percussive Sounds

Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once. In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref>

As a condition of the environments available to them, composers of music with huge reverb times tend to use mostly sustained sounds that will be supported by the reverberation of the space. Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space.

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

===See Also===

*[[Reverberation]]
*[[Deep Listening Band]]
*[[Room modes]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T22:03:20Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of a huge reverb sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Fig. 2: Time x Amplitude Graph of a sound with long reverb tail. Source: Own work]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Fig. 3: Time x Amplitude graph of a bath house's space signature, generated with Waves IR-1 from their IR library Source: Own work.]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Fig. 4: Time x Amplitude graph of an Impulse Response of a Russian Synagogue, generated with Waves IR-1 from their IR library. Source: Own Work ]]

===How Sounds Behave with in Environments Huge Reverb Times===

'''Percussive Sounds'''
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T21:58:21Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Fig. 2: Time x Amplitude Graph of a sound with long reverb tail. Source: Own work]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Fig. 3: Time x Amplitude graph of a bath house's space signature, generated with Waves IR-1 from their IR library Source: Own work.]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Fig. 4: Time x Amplitude graph of an Impulse Response of a Russian Synagogue, generated with Waves IR-1 from their IR library. Source: Own Work ]]

===How Sounds Behave with in Environments Huge Reverb Times===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T21:55:34Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay. Figure 2. shows a Time x Amplitude graph of a sound in a highly reverberant space, and divides the waveform into the source, the early reflections and the decay.
[[File:Graph of a Huge Reverb Time,.png|thumb|Time x Amplitude Graph of a sound with long reverb tail]]

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

[[File:Waves IR-1 Impulse response for Bathhouse.png|thumb|Time x Amplitude graph of an Impulse Response of a bathhouse, generated with Waves IR-1 from their IR library]]
[[File:Waves IR-1 Impulse Response for Russian Synogogue.png|thumb|Time x Amplitude graph of an Impulse Response of a bathhouse, generated with Waves IR-1 from their IR library.]]

===How Sounds Behave with in Environments Huge Reverb Times===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T21:53:12Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref> The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay.

Figures 3 and 4 show two different modelled spaces in Time x Amplitude graphs from the Waves IR-1, a digital reverb plug-in that mimics specific space signatures as precisely as a computer possibly can. It uses Impulse Response technology, where a sweep of all the audible frequencies is played from a speaker in a space and the resulting reverberation is measured with microphones. The measurements are then put into an algorithm that gives a model of the space. In the diagram, you can see how the room modes affect the consistency of the amplitude of the decay. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Sounds Behave with in Environments Huge Reverb Times===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T21:13:25Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Reverb or Space Signature===

Every space has a "signature" - or a reverb that's unique to a specific space. Music with huge reverb times is defined by its dense and long space signature. Here are some of the fundamental factors that make up that signature:

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” ''Recording'': url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

A space's signature isn't only a result of its modes - there are many other aspects. Early reflections are the sound that reaches a perceiver before the decay of the reverb, around 50 - 80 milliseconds. This part of the reverberation tail orients a sound in a listeners perceptual field - if the sound source is to the left, the early reflections on the left will be heard first, giving the brain the necessary information to locate the sound.<ref>Foley, Dennis. “Early Reflections vs Reverb: Why Do They Matter?” ''Acoustic Fields'': url: http://www.acousticfields.com/early-reflections-vs-reverb-why-do-they-matter/</ref>

The late reflections, or the decay, is the rest of the time until the sound energy is has been fully absorbed into the environment. In music with huge reverb times, this aspect is essential - music composed with heavy reverberation in mind will always rely on a long, dense decay.

Figure 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Sounds Behave with in Environments Huge Reverb Times===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T20:39:04Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Room Modes===

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: Wiki Commons]]

Because of these increases of amplitude at certain frequencies (modes), every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T20:36:07Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Room Modes===

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest (first) mode will have a wavelength, and so on. Figure 1 is a diagram of various room modes between two walls. The second mode will correspond to the frequency of a 2.5' wavelength, and so on. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Https://upload.wikimedia.org/wikipedia/commons/7/71/Onde stationnaire vitesse tuyau ouvert trois modes.svg|framed|The first 3 modes between two hard walls. Source: WikiCommons]]

Because of these increases of amplitude at certain frequencies (modes), every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T20:32:52Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Room Modes===

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest mode will have a wavelength of 5'. Figure 1 is a diagram of various room modes between two walls.<ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>
[[File:Https://upload.wikimedia.org/wikipedia/commons/7/71/Onde stationnaire vitesse tuyau ouvert trois modes.svg|thumbnail|right|The first 3 modes of a room, between two hard walls. Source: wikicommons]]

Because of these increases of amplitude at certain frequencies (modes), every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T20:31:49Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Room Modes===

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. Since rooms tend to be made with parallel walls of hard, reflective materials, standing waves are unavoidable. A room's modes then are defined by the distances between any walls, the floor, the ceiling, or any other surface. The lowest mode will correspond to the longest distance between two walls in the room; for example, if a room is 8'x10'x8', the lowest mode will have a wavelength of 5'. Figure 1 is a diagram of various room modes between two walls.
[[File:Https://upload.wikimedia.org/wikipedia/commons/7/71/Onde stationnaire vitesse tuyau ouvert trois modes.svg|thumbnail|right|The first 3 modes of a room, between two hard walls. ]]
<ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>

Because of these increases of amplitude at certain frequencies (modes), every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T20:23:55Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Room Modes===

All rooms (and any other reflective environments) have a series of modes, which are frequencies at which the room naturally resonates. When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequencies corresponding to the wavelength. A room's modes correspond to .

<ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>

Because of these increases of amplitude at certain frequencies (modes), every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T20:07:58Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver hears this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Room Modes===
All rooms (and even reflective outdoor environments) have a series of modes, or frequencies at which the room resonates. Room modes occur at frequencies with wavelengths that match up to the dimensions of the room. The resonance is produced because a standing wave occurs at this frequency.

When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequency corresponding to the wavelength. Room modes are these frequencies. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>

Every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature would include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T19:41:20Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver would hear this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

===Room Modes===
All rooms (and even reflective outdoor environments) have a series of modes, or frequencies at which the room resonates. Room modes occur at frequencies with wavelengths that match up to the dimensions of the room. The resonance is produced because a standing wave occurs at this frequency.

When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequency corresponding to the wavelength. Room modes are these frequencies. <ref>Ross, Bob, “Room Acoustics Fundamentals: Basics of nodes and standing waves.” Recording: url: http://www.recordingmag.com/resources/resourceDetail/224.html</ref>

Every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature would include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

[Good start - obviously needs the diagrams you reference in the text - CEW]

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-06T19:02:24Z

MatthewPapadopoulos:

[[Category:PHYS341-2017|Music with Huge Reverb Times]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off the surfaces surrounding it, creating a secondary echo sound. A perceiver would hear this reflection before, after, or simultaneously to the source sound. Environments that reflect enough sound to be considered to have long or "huge" reverberation times are made of hard materials such as rock and metal - such surfaces are the most reflective. Hence environments like large halls, stadiums and churches as well as artificial reverberation units provide the reverb times necessary to qualify (1.5 seconds and up).

===Room Modes===
All rooms (and even reflective outdoor environments) have a series of modes, or frequencies at which the room resonates. Room modes occur at frequencies with wavelengths that match up to the dimensions of the room. The resonance is produced because a standing wave occurs at this frequency.

When a wavelength is equal to one half of any of the distances between two parallel surfaces, or any whole number multiple thereof, a standing wave occurs. Standing waves are a phenomena in which a sound wave hits and reflects off of a boundary in such a way that it’s perfectly in phase with itself, causing a rise in volume of the frequency corresponding to the wavelength. Room modes are these frequencies.

Every space has a "signature" - or a reverb that's unique to a specific space's modes. Aspects of this signature would include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Furthermore, standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will enhance certain frequencies and silence others. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles at play in any given space with variables of velocity and temperature, so even the most powerful computers cannot reproduce the effect of a natural room. <ref>Sterne, Johnathan. "Space Within Space: Artificial Reverb and the Detachable Echo". </ref>

{{Help Nav}}
__NOEDITSECTION__
__TOC__

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb sound, until the sound pressure level drops 60 dB or a millionth of the sound's initial volume - this is usually measured in seconds.

===Percussive Sounds vs Sustained Sounds with Long Reverb Times===
Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space[feed energy into the space for the duration of the sustain], until, for example, the violin player stops bowing. This results in a buildup of [sound energy until the input rate equals the absorption rate - CEW] reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

[Good start - obviously needs the diagrams you reference in the text - CEW]

--room modes. 3d, vertical, horizontal. lowest mode is the longest dimension of the room.

--reverberation times measured in long reverb spaces... (the stairwell, percussive sound, singing sound)

--controlled by size shape ((surfaces audience (absorption) ))

--an example - the Deep Listening Band in the Cistern

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.

Music with huge reverb times can be heard in environments with these types of acoustics (lots of reflective surfaces), or it can be generated artificially. The two can be described using similar terms despite the discrepancy in the ways in which the reverb is generated.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-04T00:05:16Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-03T18:36:35Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-04-03T18:27:27Z

MatthewPapadopoulos:

Thread:User talk:Chris Waltham/article on the tamurica

2017-03-27T21:41:54Z

MatthewPapadopoulos: New thread: article on the tamurica

Hi tamurica writer, cool project. I feel like I know everything about it now except for what it sounds like. I’ve gone through your writing and bracketed words that I think are unnecessary and square-bracketed some words, punctuation and structural stuff that I’ve added or changed to help with sentence flow. I’ve put brackets around some simple typos too just to give evidence to the doctor that I’ve done my job… so sorry for that, I would have just fixed them. It’s dry and subjectivity-free, good job!
I mostly took out a lot of adverbs and adverbial clauses. There are also a some information that laypeople might not get, which I made note of in the text. One example is, why are the thinner and tighter strings lower in volume?

Anyways, very cool, and thanks for your comments on my article as well.
Best
-->

 The tamburica (also called tambura) is a string instrument that is commonly found in art, folklore, and folk music in Southern and Central Europe, specifically in Croatian and Serbian music and culture. (Specifically) the tamburica itself is an adaptation of the long-necked lute, which was adapted in the Balkans as various versions [and] became the pandora in Bulgaria, the bandura in Ukraine, and the balalaika and the domra in Russia. [1]
The tamburica was originally a solo instrument; [sentence break] however, it has been adapted for playing in an orchestral and group setting, and various tamburica orchestras exist all over the world. [2]

Types of Tamburicas
There are various types of tamburicas that are played in orchestral settings, (all) with different string arrangements and tunings. Each instrument serves a different [specific] function. The prim, or bisernica, is the smallest and most high-pitched instrument. It is used typically as a lead instrument or melody instrument. (Typically), this instrument has two single strings and two double strings, and is tuned in fourths (E, A, D, G), with E as the lowest string. This instrument (typically) has multiple small holes as opposed to one large one [with some exceptions]. The brać, or basprim is larger than the bisernica [and it] also serves as a melody or lead instrument. Its strings are the same as the bisernica[‘]s, and it is tuned the same way. This instrument is structured similarly to the guitar [— it] has a similar-looking body and one large hole [— but like the bisernica, it] has two double strings and two single strings. The čelo and čelović are larger than the brac, and (tend to) serve different functions - they fill out the harmonies and tend to play lower parts. These instruments (typically) have four single strings each. The tuning is the same as the bisernica and brać. The bugarija or kontra serves (the function of) [as] a rhythm instrument and tends to play (on) the off-beat. This instrument is not tuned the same as the others; rather, it is tuned in thirds, (typically[often]) G-B-D. The number of strings depends on the construction; either it has three sets of double strings, or two sets of double string[s] and a single string. The bas, or berda, is the largest instrument (,) and works in conjunction with the bugarija to provide rhythm for the band. It is played upright, much like a Western upright bass. It has a similar shape to the upright bass as well with f-holes much like a violin. It has four strings, and is tuned E-A-D-G, with E as the lowest string.
The instruments, with the occasional exception of the berda, are played using picks. These picks can made from plastic, animal horns, or leather; [sentence break] however, instruments with heavier and thicker strings (such as the čelo and the berda) are typically played with animal horn picks [,] as the picks are more durable.
((Additionally)), other instruments are also included in orchestral playing. [Because regions of Croatia and Serbia were greatly influenced by neighbouring regions and travellers from across Europe,] the violin (( (as used in Western music) )) is used as well as the glockenspiel and other European instruments.
  
Construction
The tamburica is made up of three primary parts.
▪ The body is typically hollow, and retains a similar structure to its predecessor, the lute. It is covered with a sound board made of [a] softwood (,) such as fir or spruce, and its hull is (typically[usually, often]) made of maple or cherry. [3]The upper part of the body usually contains a darker piece (that is usually a) piece of hardwood. This is due to the fact that the softwood soundboard could be hit by the picks during playing, which could lead to discolouration of the instrument or damage of the soundboard (itself).[4]Depending on the instrument, either several small holes (bisernica) or one large hole (brač/čelović/čelo/bugarija) are drilled onto the soundboard. ((These holes serve the same purpose as holes in Western instruments)); they are used to project the amplified sound in the body of the instrument. A bridge, for the strings [to do what for the strings?], is located on the soundboard. The bridge has notches specialized for the specific number of strings of the instrument. The strings, past [beyond] the bridge, are wrapped around nails at the end of the instrument, and these nails (also called buttons or buckles) are covered by either a metal part or a piece of leather, not only for aesthetic purposes, but to ensure that nothing disrupts the nails (as this could potentially affect tuning).
▪ The neck is connected to the body, and is (typically) made of hardwoods such as ebony. One side is curved without edges, and one side is flat. The flat side has raised notches for frets, and pressing on these frets results in different pitches. The frets provide chromatic steps. Several frets contain white circles (sometimes made of pearl), and the function of these circles is to aid in playing and to serve as guides. At the very end of the neck, connecting the neck to the head, there is a small piece or either wood or bone, and similarly to the bridge, it has notches for the strings as well.
▪ The head is at the very end of the neck. Although the head has taken various shapes over time, typically it either is flat at the top or curved in a semi-spiral shape. It is typically made from the same wood as the neck. The head contains pins that vary in number - each string receives a pin, and the number of strings on each tamburica is variable in number. The pins are turned by keys to tune the tamburica - the tighter the string [is wrapped around the pin], the higher the pitch of the string.
After construction, the tamburica is typically varnished (as well). The varnish may change the colour of the wood, to the customer/musician's liking. Some tamburicas are darker in colour, while some try to retain the natural colour of the wood, but either way, the instrument typically has a sheen to it due to varnish.

Physics and Acoustics
The wood of the instrument is conducive to sound production, much like other string instruments: [sentence break] The softwood of the soundboard, (such as fir or maple (repeated information)), means that sound created by the instrument is not impeded by the wood; rather, the vibrations are passed on to the instrument's body, resulting in a fuller and more radiant sound. Additionally, the strings of the instrument are equally as conducive to sound production. The strings that are tuned higher are often paired, such that the higher strings, while being thinner and tighter, are still loud enough. [why are the thinner and tighter strings lower in volume??]
(Despite being different instruments than the guitar or other string instruments), the tamburica behaves similarly to other stringed instruments such as the violin or guitar. The primary air mode of the bisernica sits at 340 Hz, and the primary wood mode is at 740 Hz. The bisernica in particular is a source of interest due to the fact that the instrument does not contain one large hole; [sentence break, Instead] (rather), the instrument has several small holes in its soundboard to mimic the effect of the single large hole in a brać or bugarija.
In measurements comparing vibration of the instrument with closed holes as opposed to open holes, a difference is clear (to see): closing the holes does not allow the air to escape from the instrument, preventing (as loud of a volume as [the full volume possible]) when the holes are open and the air is free to move. Peak volumes can be seen at the primary air wood and the primary wood mode when volume is plotted against frequency, and the difference in open and closed holes is also clear.

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-17T18:09:15Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-17T18:07:21Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-17T06:05:58Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-17T06:02:32Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-17T05:50:46Z

MatthewPapadopoulos:

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-17T05:49:19Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|MusicWithHugeReverbTimes]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off and is absorbed into another medium, creating a secondary sound to the source sound. A perceiver would hear this reflection before, after, or simultaneously to the source sound. Large halls, stadiums and churches provide the reverb times necessary to qualify as "long" or "huge". Music with huge reverb times can be divided into two, based on the process of reverb generation: that with natural reverb, and that with artificial. The two have similar effects — artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.
{{Help Nav}}
__NOEDITSECTION__
__TOC__

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "decay", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb, until it's inaudible - this is usually measured in seconds. Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical. Drums, wood blocks and tambourines are good examples of this kind of instrument - if struck once.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space, until, for example, the violin player stops bowing. This results in a buildup of reverb on top of the source sound as the source excites the resonant frequencies of the particular space. Fig 2. plots this on another Time x Amplitude graph.

Every space has a "signature" - or a reverb that's unique to a specific space. Aspects of this signature would include how early reflections and the decay behave, how long the reverberation time is, and the frequencies at which the room resonates, reflects or absorbs. Fig. 3 shows two Time x Amplitude graphs from the Waves IR-1, a digital reverb that mimics specific space signatures as precisely as a computer possibly can. There are billions of air particles in any given space with variables of velocity and temperature, so even the most powerful computers can't reproduce the effect of a natural room.

Standing waves can occur when sound is reflected off of two surfaces parallel to one another, like a floor and ceiling. This can cause phasing of these sound waves, which will excite certain frequencies and silence others.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation usually results in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

[[File:vibr_string.jpg|thumbnail|Fig.1. Vibrating strings of a Gothic Harp: note the elliptical motion of the plucked string on the right.]]

Strings define the musical note, but they are thin and cannot move much air and therefore produce little sound on their own. It is the sound box that produces the necessary volume of sound. All sound boxes consist of a thin shell, usually wooden, with a hole – or several holes in the case of a harp. Harp [https://en.wikipedia.org/wiki/Sound_hole sound holes] usually do double-duty as a means to attach strings, unless the harp is pre-1750 and the strings attach from the front<ref>Chris Waltham, ''The Harp'' in Science of String Instruments, ed. T. Rossing (Springer 2012)</ref>. However, even old harps have sound holes, and their presence is crucial. This article attempts to explain why harp sound boxes are wooden structures with holes, and suggests a simple experiment to demonstrate how they work.

===How Soundboxes Work===

There is five thousand years of evolution behind the modern harp, from the Pu-Abi harp to the present<ref>Rensch R., ''Harps and Harpists''. Indiana University Press, Bloomington (1998).</ref>, and the salient features of the sound box are as follows. First of all the sound box should be as large as is practically possible, because large areas radiate sound better than small ones do. Secondly, the sound box should be light, because it has to be driven to vibrate by strings of very small mass. Thirdly, it has to be very strong to withstand the string tension. The second and third requirements sit uneasily together, but this is a common engineering dilemma: light is easy, strong is easy, but both is hard. Airplanes and boats have the same problem, which is why the inside of a harp sound box bears some resemblance to the [https://en.wikipedia.org/wiki/Monocoque monocoque] shell of a kayak or an aircraft fuselage. Lastly and more subtley, it has to radiate sound well over a broad range of frequencies, and this is where the holes come in.

Any box made out of a stiff material will vibrate at a number of different frequencies, depending on how it is excited. Tap any container like an empty coffee tin in various places and listen; different tones will be heard. These frequencies in general bear no relationship to those of a musically defined scale (unless of course the structure is a Trinidadian [https://en.wikipedia.org/wiki/Steelpan Steelpan], in which case great effort has gone into ensuring that it does). The trick is make a sound box vibrate in ranges of frequencies by spreading the vibrational frequencies out to include those that the strings are trying to excite; this is where the enclosed air and the sound holes become very important.

The purpose of a sound box is to take the vibrational energy of a string and radiate it as sound. For various reasons it is relatively easy to do this efficiently at the higher frequencies of the audible range (particularly over 1000 Hz). It is much easier to shout at high frequencies than at low ones. In addition the ear is very sensitive to high frequencies, another reason why electronic alarms have annoying high pitches. As a result, instrument makers put their most strenuous efforts into radiating sound at the low end of the audible range – around 100-500 Hz – a range that is crucial to the character of the instrument’s sound. Consider a sound box of any string instrument: the two most important vibrating parts here are the top plate (the one attached to the strings, i.e. the soundboard) and the enclosed air. These two parts behave like two pendulums connected with a floppy spring, or what physicists call [https://en.wikipedia.org/wiki/Oscillation#Coupled_oscillations "coupled oscillators"], as shown in Fig.2.

[[File:pendula.png|thumbnail|Fig.2. Two lowest vibration modes of coupled pendula. When the pair swing in the same direction, they do so at a lower frequency than when they swing in opposite directions. In our analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the sound holes, and spring to be the bulk of the air in the soundbox.]]

====Coupled Oscillator Model====

There are two primary ways these pendula can oscillate – both in the same direction or each in the opposite direction from the other; these motions are “[https://en.wikipedia.org/wiki/Normal_mode normal modes]”. The mode where the pendula vibrate in the same direction has a lower frequency than when they are moving opposite to each other. In the former case the spring isn’t playing a part, but in the latter case it is.

Now consider a harp sound box. Push down on the top plate and a small amount of air squeezes out of the sound holes at the back (Fig.3a). When the top plate is tapped, the plate vibrates up and down for a second or so. The air does likewise, like the air in the neck of a bottle vibrates when blown over the top. When the plate moves inward, the air moves out, just as two pendula moving in the same direction. This simple mechanism works at low frequencies – about 150 Hz or less typically. At higher frequencies, at about 200 Hz, the air vibration lags behind that of the plate and starts to move in when the plate moves in, and out when the plate moves outwards (Fig. 3b)<ref>F. Gautier, J.-L. Le Carrou and Doutaut V., ''Faire vibrer l’air avec une corde''. Pour la Science Vol. 373 pp.46-51 (2008) (in French).</ref>. In the pendulum analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the soundholes, and spring to be the bulk of the air in the sound box. Unlike the pendulum diagram, the moving parts of the harp are not the same; the mobile part of the soundboard weighs several hundred grams (of the order of a pound) whereas only about 5 grams of air moves (the weight of two pennies). If the masses were closer together in size, the spread between the frequencies of the two modes would be too great<ref> Why? Give reference</ref>.

[[File:aurora_modes.png|thumbnail|Fig.3. Primary vibrational motion of a harp soundboard and the air in the necks of the soundholes: (a) soundboard out, air in and vice versa (lower frequency); (b) soundboard out, air out and vice versa (higher frequency).]]

====Sound Radiation====

The low frequency interaction of air and sound box produces two modes which radiate a lot of sound at their two resonant frequencies. The vibration of the soundboard is transmitted to surrounding air, and the air vibration in the sound holes produces sound directly. Due to energy losses in the wood, these are not well-defined frequencies, and the instrument radiates fairly well between these two frequencies also<ref> Why? Give reference</ref>. The frequency spread is one reason a wood like spruce is preferred for soundboards: it is resonant but not too resonant<ref>Chris Waltham and Shigeru Yoshikawa, ''Acoustics of Wood'', in Systematic Musicology, ed. R. Bader (Springer 2017), in press.
</ref>. A sheet of aluminum would be stronger and more resonant, but would only vibrate at very well-defined frequencies and not the ranges of frequencies we desire. It is easier to produce sound at high frequencies than low, and thus this mechanism also radiates sound well above 200 Hz. So here is a way of ensuring that the instrument works over a broad range of low frequencies. A simple experiment is to put masking tape over the of a guitar or violin, or by block the sound holes of a harp with thick pieces of styrofoam, and to note how the sound quality changes.

To summarize, what the holes do is to spread out the resonant frequencies of the sound box, so the strings can set the air around the sound box in motion and thus produce audible sound. The frequency spread is achieved by coupling the soundboard to a small amount of air in the necks of the sound holes that can move with or against the soundboard. For more technical details on this mechanism, see Ref.<ref>Weinreich G. ''What science knows about violins and what it doesn’t know''. American Journal of Physics Vol. 61, pp.1067-1077 (1993) </ref>.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-16T20:56:45Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|MusicWithHugeReverbTimes]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Natural [https://en.wikipedia.org/wiki/Reverberation reverberation] occurs when a sound wave radiates from its source and then reflects off and is absorbed into another medium, creating a secondary sound to the source sound. A perceiver would hear this reflection before, after, or simultaneously to the source sound. Large halls, stadiums and churches provide the reverb times necessary to qualify as "long" or "huge". Music with huge reverb times can be divided into two, based on the process of reverb generation: that with natural reverb, and that with artificial. The two have similar effects — artificial reverb is a simulation of what occurs naturally. The natural psychoacoustic phenomenon are synthetically transformed into a highly malleable set of parameters.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.
{{Help Nav}}
__NOEDITSECTION__
__TOC__

===How Long Reverb Times Function===

All reverberation is the result of sound waves reflecting from a surface. When a listener hears sound in a reverberant environment, they hear the source sound, the early reflections and the tail of that sound. Early reflections are a set of more distinctly separate echoes which return to the listener just before the less distinct "tail", which accounts for most of the reverb's sound. "Reverberation time" refers to the entire duration of reverb, usually measured in seconds. Using a short, percussive sound, it's easy to plot how reverberation functions on a graph. <ref>Needs reference!.</ref>. Fig. 1 show how a short percussive source sound and the resulting reverberations reach a perceiver, with time on the horizontal and amplitude of reverb on the vertical.

Sustained sounds, such as the sound of an organs or bowed instruments, function differently because they feed a consistent sound into the reverberant space, until, for example, the violin player stops bowing. This results in a buildup of reverb on top of the source sound as the source excites the resonant frequencies of the particular space.

In highly reverberant spaces, repeated percussive sounds cause a buildup of sound waves within the space. In this situation may result in the perception of a kind of sonic mush, which is why music made in environments with no reverberation (open spaces outdoors) tend to be more rhythmically complex.<ref>Byrne D. ''How Music Works'', (2010).</ref> As a condition of the environments available to them, composers of music with huge reverb times tend to use more sustained sounds that will be supported by the reverberation of the space.

Standing waves occur when... Phase interference from standing waves.

Resonances, harmonics

What kinds of materials reverberate what kinds of harmonics? Spring reverb - harsh, midrange harmonics

<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>

[[File:vibr_string.jpg|thumbnail|Fig.1. Vibrating strings of a Gothic Harp: note the elliptical motion of the plucked string on the right.]]

Strings define the musical note, but they are thin and cannot move much air and therefore produce little sound on their own. It is the sound box that produces the necessary volume of sound. All sound boxes consist of a thin shell, usually wooden, with a hole – or several holes in the case of a harp. Harp [https://en.wikipedia.org/wiki/Sound_hole sound holes] usually do double-duty as a means to attach strings, unless the harp is pre-1750 and the strings attach from the front<ref>Chris Waltham, ''The Harp'' in Science of String Instruments, ed. T. Rossing (Springer 2012)</ref>. However, even old harps have sound holes, and their presence is crucial. This article attempts to explain why harp sound boxes are wooden structures with holes, and suggests a simple experiment to demonstrate how they work.

===How Soundboxes Work===

There is five thousand years of evolution behind the modern harp, from the Pu-Abi harp to the present<ref>Rensch R., ''Harps and Harpists''. Indiana University Press, Bloomington (1998).</ref>, and the salient features of the sound box are as follows. First of all the sound box should be as large as is practically possible, because large areas radiate sound better than small ones do. Secondly, the sound box should be light, because it has to be driven to vibrate by strings of very small mass. Thirdly, it has to be very strong to withstand the string tension. The second and third requirements sit uneasily together, but this is a common engineering dilemma: light is easy, strong is easy, but both is hard. Airplanes and boats have the same problem, which is why the inside of a harp sound box bears some resemblance to the [https://en.wikipedia.org/wiki/Monocoque monocoque] shell of a kayak or an aircraft fuselage. Lastly and more subtley, it has to radiate sound well over a broad range of frequencies, and this is where the holes come in.

Any box made out of a stiff material will vibrate at a number of different frequencies, depending on how it is excited. Tap any container like an empty coffee tin in various places and listen; different tones will be heard. These frequencies in general bear no relationship to those of a musically defined scale (unless of course the structure is a Trinidadian [https://en.wikipedia.org/wiki/Steelpan Steelpan], in which case great effort has gone into ensuring that it does). The trick is make a sound box vibrate in ranges of frequencies by spreading the vibrational frequencies out to include those that the strings are trying to excite; this is where the enclosed air and the sound holes become very important.

The purpose of a sound box is to take the vibrational energy of a string and radiate it as sound. For various reasons it is relatively easy to do this efficiently at the higher frequencies of the audible range (particularly over 1000 Hz). It is much easier to shout at high frequencies than at low ones. In addition the ear is very sensitive to high frequencies, another reason why electronic alarms have annoying high pitches. As a result, instrument makers put their most strenuous efforts into radiating sound at the low end of the audible range – around 100-500 Hz – a range that is crucial to the character of the instrument’s sound. Consider a sound box of any string instrument: the two most important vibrating parts here are the top plate (the one attached to the strings, i.e. the soundboard) and the enclosed air. These two parts behave like two pendulums connected with a floppy spring, or what physicists call [https://en.wikipedia.org/wiki/Oscillation#Coupled_oscillations "coupled oscillators"], as shown in Fig.2.

[[File:pendula.png|thumbnail|Fig.2. Two lowest vibration modes of coupled pendula. When the pair swing in the same direction, they do so at a lower frequency than when they swing in opposite directions. In our analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the sound holes, and spring to be the bulk of the air in the soundbox.]]

====Coupled Oscillator Model====

There are two primary ways these pendula can oscillate – both in the same direction or each in the opposite direction from the other; these motions are “[https://en.wikipedia.org/wiki/Normal_mode normal modes]”. The mode where the pendula vibrate in the same direction has a lower frequency than when they are moving opposite to each other. In the former case the spring isn’t playing a part, but in the latter case it is.

Now consider a harp sound box. Push down on the top plate and a small amount of air squeezes out of the sound holes at the back (Fig.3a). When the top plate is tapped, the plate vibrates up and down for a second or so. The air does likewise, like the air in the neck of a bottle vibrates when blown over the top. When the plate moves inward, the air moves out, just as two pendula moving in the same direction. This simple mechanism works at low frequencies – about 150 Hz or less typically. At higher frequencies, at about 200 Hz, the air vibration lags behind that of the plate and starts to move in when the plate moves in, and out when the plate moves outwards (Fig. 3b)<ref>F. Gautier, J.-L. Le Carrou and Doutaut V., ''Faire vibrer l’air avec une corde''. Pour la Science Vol. 373 pp.46-51 (2008) (in French).</ref>. In the pendulum analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the soundholes, and spring to be the bulk of the air in the sound box. Unlike the pendulum diagram, the moving parts of the harp are not the same; the mobile part of the soundboard weighs several hundred grams (of the order of a pound) whereas only about 5 grams of air moves (the weight of two pennies). If the masses were closer together in size, the spread between the frequencies of the two modes would be too great<ref> Why? Give reference</ref>.

[[File:aurora_modes.png|thumbnail|Fig.3. Primary vibrational motion of a harp soundboard and the air in the necks of the soundholes: (a) soundboard out, air in and vice versa (lower frequency); (b) soundboard out, air out and vice versa (higher frequency).]]

====Sound Radiation====

The low frequency interaction of air and sound box produces two modes which radiate a lot of sound at their two resonant frequencies. The vibration of the soundboard is transmitted to surrounding air, and the air vibration in the sound holes produces sound directly. Due to energy losses in the wood, these are not well-defined frequencies, and the instrument radiates fairly well between these two frequencies also<ref> Why? Give reference</ref>. The frequency spread is one reason a wood like spruce is preferred for soundboards: it is resonant but not too resonant<ref>Chris Waltham and Shigeru Yoshikawa, ''Acoustics of Wood'', in Systematic Musicology, ed. R. Bader (Springer 2017), in press.
</ref>. A sheet of aluminum would be stronger and more resonant, but would only vibrate at very well-defined frequencies and not the ranges of frequencies we desire. It is easier to produce sound at high frequencies than low, and thus this mechanism also radiates sound well above 200 Hz. So here is a way of ensuring that the instrument works over a broad range of low frequencies. A simple experiment is to put masking tape over the of a guitar or violin, or by block the sound holes of a harp with thick pieces of styrofoam, and to note how the sound quality changes.

To summarize, what the holes do is to spread out the resonant frequencies of the sound box, so the strings can set the air around the sound box in motion and thus produce audible sound. The frequency spread is achieved by coupling the soundboard to a small amount of air in the necks of the sound holes that can move with or against the soundboard. For more technical details on this mechanism, see Ref.<ref>Weinreich G. ''What science knows about violins and what it doesn’t know''. American Journal of Physics Vol. 61, pp.1067-1077 (1993) </ref>.

===See Also===

*[[Reverberation]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-16T19:06:17Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|MusicWithHugeReverbTimes]]

<big><big><big>Music with Huge Reverb Times</big></big></big>

Music with huge reverb [https://en.wikipedia.org/wiki/Reverberation] times can be divided into two, based on the process of reverb generation: that with natural reverb, and that with artificial. The two have similar effects — artificial reverb is a simulation of what occurs naturally, but with highly malleable parameters.

Natural reverberation occurs when a sound wave radiates from its source and then reflects off of a surface, creating a secondary sound just after the first. A perceiver would hear this reflection before, after, or simultaneously to the source sound. Large halls, stadiums and churches would normally provide this type of sound.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.
{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Structure of a Concert Harp===

All [https://en.wikipedia.org/wiki/String_instrument string instruments] have a set of thin, taught strings that vibrate at a [[fundamental frequencyhttps://en.wikipedia.org/wiki/Fundamental_frequency|fundamental frequency]] with many harmonic overtones. On a harp these strings are set into vibration by plucking, and this vibration is transmitted to a soundboard, which anchors one end of each string. The basic phenomenology of string motion is dealt with in standard textbooks<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>, although many aspects are still poorly understood<ref>Needs reference!.</ref>. Fig. 1 shows how harp strings move after plucking, whirling around in small ellipses. It is this motion that excites the soundboard into vibration and causes it to radiate sound. The easiest way to see the motion is to pluck some of the lower strings under illumination from a fluorescent light. Fluorescent lights flicker at 120 Hz, giving a stroboscopic effect that appears to stop the string motion at various points in each cycle of vibration.

[[File:vibr_string.jpg|thumbnail|Fig.1. Vibrating strings of a Gothic Harp: note the elliptical motion of the plucked string on the right.]]

Strings define the musical note, but they are thin and cannot move much air and therefore produce little sound on their own. It is the sound box that produces the necessary volume of sound. All sound boxes consist of a thin shell, usually wooden, with a hole – or several holes in the case of a harp. Harp [https://en.wikipedia.org/wiki/Sound_hole sound holes] usually do double-duty as a means to attach strings, unless the harp is pre-1750 and the strings attach from the front<ref>Chris Waltham, ''The Harp'' in Science of String Instruments, ed. T. Rossing (Springer 2012)</ref>. However, even old harps have sound holes, and their presence is crucial. This article attempts to explain why harp sound boxes are wooden structures with holes, and suggests a simple experiment to demonstrate how they work.

===How Soundboxes Work===

There is five thousand years of evolution behind the modern harp, from the Pu-Abi harp to the present<ref>Rensch R., ''Harps and Harpists''. Indiana University Press, Bloomington (1998).</ref>, and the salient features of the sound box are as follows. First of all the sound box should be as large as is practically possible, because large areas radiate sound better than small ones do. Secondly, the sound box should be light, because it has to be driven to vibrate by strings of very small mass. Thirdly, it has to be very strong to withstand the string tension. The second and third requirements sit uneasily together, but this is a common engineering dilemma: light is easy, strong is easy, but both is hard. Airplanes and boats have the same problem, which is why the inside of a harp sound box bears some resemblance to the [https://en.wikipedia.org/wiki/Monocoque monocoque] shell of a kayak or an aircraft fuselage. Lastly and more subtley, it has to radiate sound well over a broad range of frequencies, and this is where the holes come in.

Any box made out of a stiff material will vibrate at a number of different frequencies, depending on how it is excited. Tap any container like an empty coffee tin in various places and listen; different tones will be heard. These frequencies in general bear no relationship to those of a musically defined scale (unless of course the structure is a Trinidadian [https://en.wikipedia.org/wiki/Steelpan Steelpan], in which case great effort has gone into ensuring that it does). The trick is make a sound box vibrate in ranges of frequencies by spreading the vibrational frequencies out to include those that the strings are trying to excite; this is where the enclosed air and the sound holes become very important.

The purpose of a sound box is to take the vibrational energy of a string and radiate it as sound. For various reasons it is relatively easy to do this efficiently at the higher frequencies of the audible range (particularly over 1000 Hz). It is much easier to shout at high frequencies than at low ones. In addition the ear is very sensitive to high frequencies, another reason why electronic alarms have annoying high pitches. As a result, instrument makers put their most strenuous efforts into radiating sound at the low end of the audible range – around 100-500 Hz – a range that is crucial to the character of the instrument’s sound. Consider a sound box of any string instrument: the two most important vibrating parts here are the top plate (the one attached to the strings, i.e. the soundboard) and the enclosed air. These two parts behave like two pendulums connected with a floppy spring, or what physicists call [https://en.wikipedia.org/wiki/Oscillation#Coupled_oscillations "coupled oscillators"], as shown in Fig.2.

[[File:pendula.png|thumbnail|Fig.2. Two lowest vibration modes of coupled pendula. When the pair swing in the same direction, they do so at a lower frequency than when they swing in opposite directions. In our analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the sound holes, and spring to be the bulk of the air in the soundbox.]]

====Coupled Oscillator Model====

There are two primary ways these pendula can oscillate – both in the same direction or each in the opposite direction from the other; these motions are “[https://en.wikipedia.org/wiki/Normal_mode normal modes]”. The mode where the pendula vibrate in the same direction has a lower frequency than when they are moving opposite to each other. In the former case the spring isn’t playing a part, but in the latter case it is.

Now consider a harp sound box. Push down on the top plate and a small amount of air squeezes out of the sound holes at the back (Fig.3a). When the top plate is tapped, the plate vibrates up and down for a second or so. The air does likewise, like the air in the neck of a bottle vibrates when blown over the top. When the plate moves inward, the air moves out, just as two pendula moving in the same direction. This simple mechanism works at low frequencies – about 150 Hz or less typically. At higher frequencies, at about 200 Hz, the air vibration lags behind that of the plate and starts to move in when the plate moves in, and out when the plate moves outwards (Fig. 3b)<ref>F. Gautier, J.-L. Le Carrou and Doutaut V., ''Faire vibrer l’air avec une corde''. Pour la Science Vol. 373 pp.46-51 (2008) (in French).</ref>. In the pendulum analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the soundholes, and spring to be the bulk of the air in the sound box. Unlike the pendulum diagram, the moving parts of the harp are not the same; the mobile part of the soundboard weighs several hundred grams (of the order of a pound) whereas only about 5 grams of air moves (the weight of two pennies). If the masses were closer together in size, the spread between the frequencies of the two modes would be too great<ref> Why? Give reference</ref>.

[[File:aurora_modes.png|thumbnail|Fig.3. Primary vibrational motion of a harp soundboard and the air in the necks of the soundholes: (a) soundboard out, air in and vice versa (lower frequency); (b) soundboard out, air out and vice versa (higher frequency).]]

====Sound Radiation====

The low frequency interaction of air and sound box produces two modes which radiate a lot of sound at their two resonant frequencies. The vibration of the soundboard is transmitted to surrounding air, and the air vibration in the sound holes produces sound directly. Due to energy losses in the wood, these are not well-defined frequencies, and the instrument radiates fairly well between these two frequencies also<ref> Why? Give reference</ref>. The frequency spread is one reason a wood like spruce is preferred for soundboards: it is resonant but not too resonant<ref>Chris Waltham and Shigeru Yoshikawa, ''Acoustics of Wood'', in Systematic Musicology, ed. R. Bader (Springer 2017), in press.
</ref>. A sheet of aluminum would be stronger and more resonant, but would only vibrate at very well-defined frequencies and not the ranges of frequencies we desire. It is easier to produce sound at high frequencies than low, and thus this mechanism also radiates sound well above 200 Hz. So here is a way of ensuring that the instrument works over a broad range of low frequencies. A simple experiment is to put masking tape over the of a guitar or violin, or by block the sound holes of a harp with thick pieces of styrofoam, and to note how the sound quality changes.

To summarize, what the holes do is to spread out the resonant frequencies of the sound box, so the strings can set the air around the sound box in motion and thus produce audible sound. The frequency spread is achieved by coupling the soundboard to a small amount of air in the necks of the sound holes that can move with or against the soundboard. For more technical details on this mechanism, see Ref.<ref>Weinreich G. ''What science knows about violins and what it doesn’t know''. American Journal of Physics Vol. 61, pp.1067-1077 (1993) </ref>.

===See Also===

*[[Harp]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-16T19:05:36Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|MusicWithHugeReverbTimes]]

<big><big><big>Music with Huge Reverberation Times</big></big></big>

Music with huge [https://en.wikipedia.org/wiki/Reverberation] times can be divided into two, based on the process of reverb generation: that with natural reverb, and that with artificial. The two have similar effects — artificial reverb is a simulation of what occurs naturally, but with highly malleable parameters.

Natural reverberation occurs when a sound wave radiates from its source and then reflects off of a surface, creating a secondary sound just after the first. A perceiver would hear this reflection before, after, or simultaneously to the source sound. Large halls, stadiums and churches would normally provide this type of sound.

Artificial reverberation is common in recorded music and nearly ubiquitous in modern pop recording. With artificial reverberation, musicians and composers can create fantastical spaces with possible reverb times much longer than the ones heard in even the most reverberant spaces like cathedrals and arenas.
{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Structure of a Concert Harp===

All [https://en.wikipedia.org/wiki/String_instrument string instruments] have a set of thin, taught strings that vibrate at a [[fundamental frequencyhttps://en.wikipedia.org/wiki/Fundamental_frequency|fundamental frequency]] with many harmonic overtones. On a harp these strings are set into vibration by plucking, and this vibration is transmitted to a soundboard, which anchors one end of each string. The basic phenomenology of string motion is dealt with in standard textbooks<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>, although many aspects are still poorly understood<ref>Needs reference!.</ref>. Fig. 1 shows how harp strings move after plucking, whirling around in small ellipses. It is this motion that excites the soundboard into vibration and causes it to radiate sound. The easiest way to see the motion is to pluck some of the lower strings under illumination from a fluorescent light. Fluorescent lights flicker at 120 Hz, giving a stroboscopic effect that appears to stop the string motion at various points in each cycle of vibration.

[[File:vibr_string.jpg|thumbnail|Fig.1. Vibrating strings of a Gothic Harp: note the elliptical motion of the plucked string on the right.]]

Strings define the musical note, but they are thin and cannot move much air and therefore produce little sound on their own. It is the sound box that produces the necessary volume of sound. All sound boxes consist of a thin shell, usually wooden, with a hole – or several holes in the case of a harp. Harp [https://en.wikipedia.org/wiki/Sound_hole sound holes] usually do double-duty as a means to attach strings, unless the harp is pre-1750 and the strings attach from the front<ref>Chris Waltham, ''The Harp'' in Science of String Instruments, ed. T. Rossing (Springer 2012)</ref>. However, even old harps have sound holes, and their presence is crucial. This article attempts to explain why harp sound boxes are wooden structures with holes, and suggests a simple experiment to demonstrate how they work.

===How Soundboxes Work===

There is five thousand years of evolution behind the modern harp, from the Pu-Abi harp to the present<ref>Rensch R., ''Harps and Harpists''. Indiana University Press, Bloomington (1998).</ref>, and the salient features of the sound box are as follows. First of all the sound box should be as large as is practically possible, because large areas radiate sound better than small ones do. Secondly, the sound box should be light, because it has to be driven to vibrate by strings of very small mass. Thirdly, it has to be very strong to withstand the string tension. The second and third requirements sit uneasily together, but this is a common engineering dilemma: light is easy, strong is easy, but both is hard. Airplanes and boats have the same problem, which is why the inside of a harp sound box bears some resemblance to the [https://en.wikipedia.org/wiki/Monocoque monocoque] shell of a kayak or an aircraft fuselage. Lastly and more subtley, it has to radiate sound well over a broad range of frequencies, and this is where the holes come in.

Any box made out of a stiff material will vibrate at a number of different frequencies, depending on how it is excited. Tap any container like an empty coffee tin in various places and listen; different tones will be heard. These frequencies in general bear no relationship to those of a musically defined scale (unless of course the structure is a Trinidadian [https://en.wikipedia.org/wiki/Steelpan Steelpan], in which case great effort has gone into ensuring that it does). The trick is make a sound box vibrate in ranges of frequencies by spreading the vibrational frequencies out to include those that the strings are trying to excite; this is where the enclosed air and the sound holes become very important.

The purpose of a sound box is to take the vibrational energy of a string and radiate it as sound. For various reasons it is relatively easy to do this efficiently at the higher frequencies of the audible range (particularly over 1000 Hz). It is much easier to shout at high frequencies than at low ones. In addition the ear is very sensitive to high frequencies, another reason why electronic alarms have annoying high pitches. As a result, instrument makers put their most strenuous efforts into radiating sound at the low end of the audible range – around 100-500 Hz – a range that is crucial to the character of the instrument’s sound. Consider a sound box of any string instrument: the two most important vibrating parts here are the top plate (the one attached to the strings, i.e. the soundboard) and the enclosed air. These two parts behave like two pendulums connected with a floppy spring, or what physicists call [https://en.wikipedia.org/wiki/Oscillation#Coupled_oscillations "coupled oscillators"], as shown in Fig.2.

[[File:pendula.png|thumbnail|Fig.2. Two lowest vibration modes of coupled pendula. When the pair swing in the same direction, they do so at a lower frequency than when they swing in opposite directions. In our analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the sound holes, and spring to be the bulk of the air in the soundbox.]]

====Coupled Oscillator Model====

There are two primary ways these pendula can oscillate – both in the same direction or each in the opposite direction from the other; these motions are “[https://en.wikipedia.org/wiki/Normal_mode normal modes]”. The mode where the pendula vibrate in the same direction has a lower frequency than when they are moving opposite to each other. In the former case the spring isn’t playing a part, but in the latter case it is.

Now consider a harp sound box. Push down on the top plate and a small amount of air squeezes out of the sound holes at the back (Fig.3a). When the top plate is tapped, the plate vibrates up and down for a second or so. The air does likewise, like the air in the neck of a bottle vibrates when blown over the top. When the plate moves inward, the air moves out, just as two pendula moving in the same direction. This simple mechanism works at low frequencies – about 150 Hz or less typically. At higher frequencies, at about 200 Hz, the air vibration lags behind that of the plate and starts to move in when the plate moves in, and out when the plate moves outwards (Fig. 3b)<ref>F. Gautier, J.-L. Le Carrou and Doutaut V., ''Faire vibrer l’air avec une corde''. Pour la Science Vol. 373 pp.46-51 (2008) (in French).</ref>. In the pendulum analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the soundholes, and spring to be the bulk of the air in the sound box. Unlike the pendulum diagram, the moving parts of the harp are not the same; the mobile part of the soundboard weighs several hundred grams (of the order of a pound) whereas only about 5 grams of air moves (the weight of two pennies). If the masses were closer together in size, the spread between the frequencies of the two modes would be too great<ref> Why? Give reference</ref>.

[[File:aurora_modes.png|thumbnail|Fig.3. Primary vibrational motion of a harp soundboard and the air in the necks of the soundholes: (a) soundboard out, air in and vice versa (lower frequency); (b) soundboard out, air out and vice versa (higher frequency).]]

====Sound Radiation====

The low frequency interaction of air and sound box produces two modes which radiate a lot of sound at their two resonant frequencies. The vibration of the soundboard is transmitted to surrounding air, and the air vibration in the sound holes produces sound directly. Due to energy losses in the wood, these are not well-defined frequencies, and the instrument radiates fairly well between these two frequencies also<ref> Why? Give reference</ref>. The frequency spread is one reason a wood like spruce is preferred for soundboards: it is resonant but not too resonant<ref>Chris Waltham and Shigeru Yoshikawa, ''Acoustics of Wood'', in Systematic Musicology, ed. R. Bader (Springer 2017), in press.
</ref>. A sheet of aluminum would be stronger and more resonant, but would only vibrate at very well-defined frequencies and not the ranges of frequencies we desire. It is easier to produce sound at high frequencies than low, and thus this mechanism also radiates sound well above 200 Hz. So here is a way of ensuring that the instrument works over a broad range of low frequencies. A simple experiment is to put masking tape over the of a guitar or violin, or by block the sound holes of a harp with thick pieces of styrofoam, and to note how the sound quality changes.

To summarize, what the holes do is to spread out the resonant frequencies of the sound box, so the strings can set the air around the sound box in motion and thus produce audible sound. The frequency spread is achieved by coupling the soundboard to a small amount of air in the necks of the sound holes that can move with or against the soundboard. For more technical details on this mechanism, see Ref.<ref>Weinreich G. ''What science knows about violins and what it doesn’t know''. American Journal of Physics Vol. 61, pp.1067-1077 (1993) </ref>.

===See Also===

*[[Harp]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-03-14T21:05:38Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|MusicWithHugeReverbTimes]]

<big><big><big>Example Writing Project: The Sound Box of a Concert Harp</big></big></big>

The [https://en.wikipedia.org/wiki/Harp harp] is a multi-stringed musical instrument that has its strings connected directly to a [https://en.wikipedia.org/wiki/Sound_box sound box]. The sound box is the means by which the vibrational energy in the strings is radiated as sound. The sound box has its own distinctive vibrational structure unrelated to that of the strings, and thus it contributes to the acoustic character of the instrument.
{{Help Nav}}
__NOEDITSECTION__
__TOC__

===Structure of a Concert Harp===

All [https://en.wikipedia.org/wiki/String_instrument string instruments] have a set of thin, taught strings that vibrate at a [[fundamental frequencyhttps://en.wikipedia.org/wiki/Fundamental_frequency|fundamental frequency]] with many harmonic overtones. On a harp these strings are set into vibration by plucking, and this vibration is transmitted to a soundboard, which anchors one end of each string. The basic phenomenology of string motion is dealt with in standard textbooks<ref>Rossing T, Moore, R. and Wheeler P., ''Science of Sound'', Addison Wesley, New York (2001).</ref>, although many aspects are still poorly understood<ref>Needs reference!.</ref>. Fig. 1 shows how harp strings move after plucking, whirling around in small ellipses. It is this motion that excites the soundboard into vibration and causes it to radiate sound. The easiest way to see the motion is to pluck some of the lower strings under illumination from a fluorescent light. Fluorescent lights flicker at 120 Hz, giving a stroboscopic effect that appears to stop the string motion at various points in each cycle of vibration.

[[File:vibr_string.jpg|thumbnail|Fig.1. Vibrating strings of a Gothic Harp: note the elliptical motion of the plucked string on the right.]]

Strings define the musical note, but they are thin and cannot move much air and therefore produce little sound on their own. It is the sound box that produces the necessary volume of sound. All sound boxes consist of a thin shell, usually wooden, with a hole – or several holes in the case of a harp. Harp [https://en.wikipedia.org/wiki/Sound_hole sound holes] usually do double-duty as a means to attach strings, unless the harp is pre-1750 and the strings attach from the front<ref>Chris Waltham, ''The Harp'' in Science of String Instruments, ed. T. Rossing (Springer 2012)</ref>. However, even old harps have sound holes, and their presence is crucial. This article attempts to explain why harp sound boxes are wooden structures with holes, and suggests a simple experiment to demonstrate how they work.

===How Soundboxes Work===

There is five thousand years of evolution behind the modern harp, from the Pu-Abi harp to the present<ref>Rensch R., ''Harps and Harpists''. Indiana University Press, Bloomington (1998).</ref>, and the salient features of the sound box are as follows. First of all the sound box should be as large as is practically possible, because large areas radiate sound better than small ones do. Secondly, the sound box should be light, because it has to be driven to vibrate by strings of very small mass. Thirdly, it has to be very strong to withstand the string tension. The second and third requirements sit uneasily together, but this is a common engineering dilemma: light is easy, strong is easy, but both is hard. Airplanes and boats have the same problem, which is why the inside of a harp sound box bears some resemblance to the [https://en.wikipedia.org/wiki/Monocoque monocoque] shell of a kayak or an aircraft fuselage. Lastly and more subtley, it has to radiate sound well over a broad range of frequencies, and this is where the holes come in.

Any box made out of a stiff material will vibrate at a number of different frequencies, depending on how it is excited. Tap any container like an empty coffee tin in various places and listen; different tones will be heard. These frequencies in general bear no relationship to those of a musically defined scale (unless of course the structure is a Trinidadian [https://en.wikipedia.org/wiki/Steelpan Steelpan], in which case great effort has gone into ensuring that it does). The trick is make a sound box vibrate in ranges of frequencies by spreading the vibrational frequencies out to include those that the strings are trying to excite; this is where the enclosed air and the sound holes become very important.

The purpose of a sound box is to take the vibrational energy of a string and radiate it as sound. For various reasons it is relatively easy to do this efficiently at the higher frequencies of the audible range (particularly over 1000 Hz). It is much easier to shout at high frequencies than at low ones. In addition the ear is very sensitive to high frequencies, another reason why electronic alarms have annoying high pitches. As a result, instrument makers put their most strenuous efforts into radiating sound at the low end of the audible range – around 100-500 Hz – a range that is crucial to the character of the instrument’s sound. Consider a sound box of any string instrument: the two most important vibrating parts here are the top plate (the one attached to the strings, i.e. the soundboard) and the enclosed air. These two parts behave like two pendulums connected with a floppy spring, or what physicists call [https://en.wikipedia.org/wiki/Oscillation#Coupled_oscillations "coupled oscillators"], as shown in Fig.2.

[[File:pendula.png|thumbnail|Fig.2. Two lowest vibration modes of coupled pendula. When the pair swing in the same direction, they do so at a lower frequency than when they swing in opposite directions. In our analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the sound holes, and spring to be the bulk of the air in the soundbox.]]

====Coupled Oscillator Model====

There are two primary ways these pendula can oscillate – both in the same direction or each in the opposite direction from the other; these motions are “[https://en.wikipedia.org/wiki/Normal_mode normal modes]”. The mode where the pendula vibrate in the same direction has a lower frequency than when they are moving opposite to each other. In the former case the spring isn’t playing a part, but in the latter case it is.

Now consider a harp sound box. Push down on the top plate and a small amount of air squeezes out of the sound holes at the back (Fig.3a). When the top plate is tapped, the plate vibrates up and down for a second or so. The air does likewise, like the air in the neck of a bottle vibrates when blown over the top. When the plate moves inward, the air moves out, just as two pendula moving in the same direction. This simple mechanism works at low frequencies – about 150 Hz or less typically. At higher frequencies, at about 200 Hz, the air vibration lags behind that of the plate and starts to move in when the plate moves in, and out when the plate moves outwards (Fig. 3b)<ref>F. Gautier, J.-L. Le Carrou and Doutaut V., ''Faire vibrer l’air avec une corde''. Pour la Science Vol. 373 pp.46-51 (2008) (in French).</ref>. In the pendulum analogy, consider the left pendulum to be the soundboard, the right pendulum to be the air in the necks of the soundholes, and spring to be the bulk of the air in the sound box. Unlike the pendulum diagram, the moving parts of the harp are not the same; the mobile part of the soundboard weighs several hundred grams (of the order of a pound) whereas only about 5 grams of air moves (the weight of two pennies). If the masses were closer together in size, the spread between the frequencies of the two modes would be too great<ref> Why? Give reference</ref>.

[[File:aurora_modes.png|thumbnail|Fig.3. Primary vibrational motion of a harp soundboard and the air in the necks of the soundholes: (a) soundboard out, air in and vice versa (lower frequency); (b) soundboard out, air out and vice versa (higher frequency).]]

====Sound Radiation====

The low frequency interaction of air and sound box produces two modes which radiate a lot of sound at their two resonant frequencies. The vibration of the soundboard is transmitted to surrounding air, and the air vibration in the sound holes produces sound directly. Due to energy losses in the wood, these are not well-defined frequencies, and the instrument radiates fairly well between these two frequencies also<ref> Why? Give reference</ref>. The frequency spread is one reason a wood like spruce is preferred for soundboards: it is resonant but not too resonant<ref>Chris Waltham and Shigeru Yoshikawa, ''Acoustics of Wood'', in Systematic Musicology, ed. R. Bader (Springer 2017), in press.
</ref>. A sheet of aluminum would be stronger and more resonant, but would only vibrate at very well-defined frequencies and not the ranges of frequencies we desire. It is easier to produce sound at high frequencies than low, and thus this mechanism also radiates sound well above 200 Hz. So here is a way of ensuring that the instrument works over a broad range of low frequencies. A simple experiment is to put masking tape over the of a guitar or violin, or by block the sound holes of a harp with thick pieces of styrofoam, and to note how the sound quality changes.

To summarize, what the holes do is to spread out the resonant frequencies of the sound box, so the strings can set the air around the sound box in motion and thus produce audible sound. The frequency spread is achieved by coupling the soundboard to a small amount of air in the necks of the sound holes that can move with or against the soundboard. For more technical details on this mechanism, see Ref.<ref>Weinreich G. ''What science knows about violins and what it doesn’t know''. American Journal of Physics Vol. 61, pp.1067-1077 (1993) </ref>.

===See Also===

*[[Harp]]
*[[Strings]]
*[[Sound board]]

==References==
{{reflist}}

Category:PHYS 341- 2017

2017-02-15T19:48:26Z

MatthewPapadopoulos: Created page with "*one bit of page here *next bit of page here *etc"

*one bit of page here

*next bit of page here

*etc

Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-02-15T19:47:29Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|MusicWithHugeReverbTimes]]

*Here is a part of this page

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Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-02-15T19:45:12Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017|YourProject]]

*Here is a part of this page

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Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-02-15T19:38:35Z

MatthewPapadopoulos:

[[Category: PHYS 341- 2017/Music with Huge Reverb Times]]

*Here is a part of this page

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Course:PHYS341/Archive/2016wTerm2/MusicWithHugeReverbTimes

2017-02-15T19:35:13Z

MatthewPapadopoulos: Created page with "[Category: PHYS 341- 2017/Music with Huge Reverb Times] *Here is a part of this page *Here is another part"

[Category: PHYS 341- 2017/Music with Huge Reverb Times]

*Here is a part of this page

*Here is another part

Course:PHYS341/Archive/2016wTerm2/MyProjectName

2017-02-15T19:34:45Z

MatthewPapadopoulos:

[Category: PHYS 341- 2017/Orchestra Member's Effect on Sound Absorption and Reflection in a Concert Hall Setting]

Course:PHYS341/Archive/2016wTerm2/MyProjectName

2017-02-15T19:27:00Z

MatthewPapadopoulos:

[Category: PHYS 341- 2017/Music with Huge Reverb Times]

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2017-02-15T19:25:11Z

MatthewPapadopoulos: Created page with "Matthew Papadopoulos"

Matthew Papadopoulos

Course:PHYS341/Archive/2016wTerm2/Wiki project ideas

2017-02-01T00:52:06Z

MatthewPapadopoulos:

'''Topic must be about the Physics of MUSIC, not just the physics of sound.''' 
Chris Waltham "How does the choice of wood affect the sound of a Persian santur?" 
M. Pourian, https://manusantur.wordpress.com/ and Journal of Acoustic Woods, '''37''' (2016) p.239. 

-------------------------------------------------------------------------------------------------------------------------
Jonathan Kwok "Orchestra members' effect on sound absorption and reflection in concert hall setting" 
http://asa.scitation.org.ezproxy.library.ubc.ca/doi/pdf/10.1121/1.4971763 
-------------------------------------------------------------------------------------------------------------------------
Shea Oracheski "How does the temperature of a material affect its absorbing potential"

http://nvlpubs.nist.gov/nistpubs/jres/9/jresv9n2p175_A2b.pdf
-------------------------------------------------------------------------------------------------------------------------
Alfred Ko "How do a violin's f-holes contribute to its sound?" 
http://web.b.ebscohost.com/ehost/detail/detail?vid=1&sid=d8fc2370-2bfa-4beb-9245-bf55caf2d61c%40sessionmgr102&hid=128&bdata=JnNpdGU9ZWhvc3QtbGl2ZSZzY29wZT1zaXRl#AN=4299280&db=a9h

Beament, James, and Dennis Unwin. "The Hole Story." Strad 112.1332 (2001): 408. Academic Search Complete. Web. 30 Jan. 2017.
-------------------------------------------------------------------------------------------------------------------------
Andrea Wong "How does the soundpost contribute to a string instrument's sound?"
https://www.researchgate.net/profile/George_Bissinger/publication/241390846_The_Influence_of_the_Soundpost_on_the_Mechanical_Motions_of_the_Violin/links/5792486608aec89db781bf34.pdf
-------------------------------------------------------------------------------------------------------------------------
Tina Cheung "How does helium affect the frequency of the human voice?"

http://aapt.scitation.org/doi/pdf/10.1119/1.3566028
-------------------------------------------------------------------------------------------------------------------------
Diana Gil "How does the construction of a semi-hollow guitar affect the acoustics of the instrument?"

Acoustics of Guitars - Thomas D. Rossing - http://asa.scitation.org/doi/abs/10.1121/1.412720

Fundamentals of Guitar Tone - Erik V. Jansson - DOI: http://dx.doi.org/10.1121/1.2019626

Solidbody or Hollowbody ... Which is right for me?- Russell Hall - http://www.gibson.com/news-lifestyle/features/en-us/solidbody-or-hollowbody-guitar-0829-2012.aspx

Investigating the Effect of Body Geometry on the Acoustics of Electric Guitars - Mark Rau and Gary Scavone - http://asa.scitation.org/doi/10.1121/1.4950571

Engineering the Guitar: Theory and Practice - Richard Mark French
http://link.springer.com.ezproxy.library.ubc.ca/book/10.1007/978-0-387-74369-1
-------------------------------------------------------------------------------------------------------------------------
Shaula Wong "Relative Humidity and its Affect on Live Music" 
https://ccrma.stanford.edu/~jos/HarrisJASA66.pdf 
-------------------------------------------------------------------------------------------------------------------------
Matt Papadopoulos "Effects of reverberation inside the Dan Harpole Cistern at Fort Worden State Park, WA" 
http://www.newmusicbox.org/articles/cistern-chapel/ 
https://www.youtube.com/watch?v=oZ8MhEn-jm4 
-------------------------------------------------------------------------------------------------------------------------

Next person "Next topic" 
Reference to scholarly work (print or URL) - at least one good one

Course:PHYS341/Archive/2016wTerm2/Wiki project ideas

2017-02-01T00:48:03Z

MatthewPapadopoulos:

'''Topic must be about the Physics of MUSIC, not just the physics of sound.''' 
Chris Waltham "How does the choice of wood affect the sound of a Persian santur?" 
M. Pourian, https://manusantur.wordpress.com/ and Journal of Acoustic Woods, '''37''' (2016) p.239. 

-------------------------------------------------------------------------------------------------------------------------
Jonathan Kwok "Orchestra members' effect on sound absorption and reflection in concert hall setting" 
http://asa.scitation.org.ezproxy.library.ubc.ca/doi/pdf/10.1121/1.4971763 
-------------------------------------------------------------------------------------------------------------------------
Shea Oracheski "How does the temperature of a material affect its absorbing potential"

http://nvlpubs.nist.gov/nistpubs/jres/9/jresv9n2p175_A2b.pdf
-------------------------------------------------------------------------------------------------------------------------
Alfred Ko "How do a violin's f-holes contribute to its sound?" 
http://web.b.ebscohost.com/ehost/detail/detail?vid=1&sid=d8fc2370-2bfa-4beb-9245-bf55caf2d61c%40sessionmgr102&hid=128&bdata=JnNpdGU9ZWhvc3QtbGl2ZSZzY29wZT1zaXRl#AN=4299280&db=a9h

Beament, James, and Dennis Unwin. "The Hole Story." Strad 112.1332 (2001): 408. Academic Search Complete. Web. 30 Jan. 2017.
-------------------------------------------------------------------------------------------------------------------------
Andrea Wong "How does the soundpost contribute to a string instrument's sound?"
https://www.researchgate.net/profile/George_Bissinger/publication/241390846_The_Influence_of_the_Soundpost_on_the_Mechanical_Motions_of_the_Violin/links/5792486608aec89db781bf34.pdf
-------------------------------------------------------------------------------------------------------------------------
Tina Cheung "How does helium affect the frequency of the human voice?"

http://aapt.scitation.org/doi/pdf/10.1119/1.3566028
-------------------------------------------------------------------------------------------------------------------------
Diana Gil "How does the construction of a semi-hollow guitar affect the acoustics of the instrument?"

Acoustics of Guitars - Thomas D. Rossing - http://asa.scitation.org/doi/abs/10.1121/1.412720

Fundamentals of Guitar Tone - Erik V. Jansson - DOI: http://dx.doi.org/10.1121/1.2019626

Solidbody or Hollowbody ... Which is right for me?- Russell Hall - http://www.gibson.com/news-lifestyle/features/en-us/solidbody-or-hollowbody-guitar-0829-2012.aspx

Investigating the Effect of Body Geometry on the Acoustics of Electric Guitars - Mark Rau and Gary Scavone - http://asa.scitation.org/doi/10.1121/1.4950571

Engineering the Guitar: Theory and Practice - Richard Mark French
http://link.springer.com.ezproxy.library.ubc.ca/book/10.1007/978-0-387-74369-1
-------------------------------------------------------------------------------------------------------------------------
Shaula Wong "Relative Humidity and its Affect on Live Music" 
https://ccrma.stanford.edu/~jos/HarrisJASA66.pdf 
-------------------------------------------------------------------------------------------------------------------------
Matt Papadopoulos "Effects of reverberation inside the Dan Harpole Cistern at Fort Worden State Park, WA" 
http://www.newmusicbox.org/articles/cistern-chapel/ 
-------------------------------------------------------------------------------------------------------------------------

Next person "Next topic" 
Reference to scholarly work (print or URL) - at least one good one