Course:PHYS341/2018/Goals

The overarching goal of this course is that students will be able to write and speak about the topics under discussion in a qualitative but scientifically accurate manner that is understandable to an educated but otherwise non-expert audience.

Lecture 1: Physical meaning of sound, music, noise. Soundscape and evolutionary origins of hearing, language and singing. Physical function of a musical instrument. Descriptions of sound and music in plain language and what this means physically. Warning about the use of common English words that have specific scientific meanings.

Lecture 2: Vibrations as origins of musical sounds. Physical characterization of vibrations - frequency, period, amplitude, decay time. Visualization.

Lecture 3: The nature of waves in general, starting with transverse waves. What a wave is physically and how it transmits energy and information; distinction between motion of the particles of the medium and the motion of the wave.

Lecture 4: Extending previous lecture ideas to the more challenging longitudinal waves.

Lecture 5: How sound is generated and transmitted through various media. What happens at boundaries.

Lecture 6: Resonance: what causes a system to react more to one frequency than another.. How sounds interact with each other; beats

Lecture 7: Tutorial on computer-based sound visualization and analysis. Audacity, SpectrumLab, iSpectrum.

Lecture 8: Diffraction and interference. How sound goes around corners. Relationship between wavelength and size of obstructions.

Lecture 9: Complex tones: what happens when frequencies mix.

Lecture 10: Intensity and noise: meaning of sound level (dB), intensity (W/m²), phons. Frequency ranges and thresholds. Fletcher-Munson curves.

Lecture 11: Perception: how our ears and brains deal with sound. Relationship between sonogram plots and what happens in the human basilar membrane.

Lecture 12: Perception continued.

Lecture 13: Vibrating strings: physical properties, what determines the frequencies, harmonicity.

Lecture 14: Vibrating strings continued.

Lecture 15: Vibrating air columns. Acoustic pressure and velocity. Boundary conditions - open and closed pipes.

Lecture 16: Vibrating air columns continued. Vibration modes.

Lecture 17: Vibration of plates: bending, twisting modes and nodes, frequencies. Effect of stiffness, mass, geometry.

Lecture 18: How to write a wiki.

Lecture 19: Scales - how to divide the octave, human, physical and mathematical constraints.

Lecture 20: Scales continued - equal temperament and why we never use it.

Lecture 21: Combination tones - why spectra and not just single frequencies matter.

Lecture 22: Plucked strings. Soundboxes - wooden boxes with holes. Air/wood modes - influenced by material mass and thickness, size of sound holes and cavities.

Lecture 23: Bowed strings. Why and how bows work. Violin family. Soundbox structure.

Lecture 24: Acoustic woods - why wood still reigns supreme for string instruments. Quality factor in resonance.

Lecture 25: Harps, harpsichords, fortepianos and pianos - technical and material developments from the harpsichord to the modern grand.

Lecture 26: Brass instruments: valves, slides, bore shapes and what the bell does.

Lecture 27: Woodwind: action of reeds, bore and holes in controlling sounding frequencies, mode features.

Lecture 28: Percussion: modes of xylophone/marimba bars (and resonating tubes), timpani membranes and modes.

Lecture 29: Anechoic chamber tour: sound absorbing walls, reverberation time.

Lecture 30: Asian wind instruments: tubes with open/closed ends, modes of air column, free reeds.

Lecture 31: Electronic music: how to reproduce musical sounds with electromechanical, electronic and computer means.

Lecture 32: Musical architecture: room modes, surfaces, volume, absorption. Signal timing: direct and reflected sound. Reverberation time. Reflectors and diffusers in concert a halls. Different types of music for different spaces.

Lecture 33: Human perception with two ears, direction location, stereo sound recording. Direction location in the sagittal plane; pinna notch. Human voice - spectrum from vocal folds modified by formants. Vowels. Effects of aging, gender on length of vocal tract and thus the formant frequencies.

Lecture 34: Formants in the human voice, violin and erhu.