Course:Phys341 2020/Khoomei

Khoomei throat singing is one particular variant of overtone singing practiced by people in Mongolia, Inner Mongolia, Tuva, and Siberia. It can also be referred to as Tuvan throat singing or Mongolian throat singing.  Khoomei has may types of vocalization and singing. The essential feature in Khoomei is, the performer sings two or three voice types at the same time, adding overtones above a fundamental tone to form a melody.

History of Khoomei

The history of Khoomei can be traced back to the Xiongnu period, where it originally began. Ancestors in the Mongolian plateau were devoted to imitating the sounds of nature during hunting and nomadic. They thought that it was a form of effective communication and an essential way to achieve harmony with nature and the universe, to gain some potential beneficial developments of the vocal organs of the human body. The Mongols postulate that Khoomei began when their ancient ancestors in the mountains saw the bifurcations of rivers, waterfalls, and heard the echo of birds reverberated in the valleys. The ancestors were inspired by these scenes and thus begun imitating them in a process, which marked the inception of Khoomei. Khoomei has unique singing techniques, which is the reason why there are not so many Khoomei songs. There are three motives for singing Khoomei, which are to sing for beautiful natural scenery, to imitate the lovely wild animals, and to praise the steed and grassland. In terms of its musical style, Khoomei songs are mainly sung in short melodies, sometimes can also the simple long songs, but there are not many lengthy songs for Khoomei. From the history of Khoomei, it can be noted that throat singing is a product of the era of the hunting culture in the Mongolian plateau.

Introduction

It is important to note that at first, when singing Khoomei, a singer needs to focus on the use of throat and chest to produce a loud fundamental tone. The intensity of making this sound should be much higher than general talking and singing. Secondly, the singer needs to use special techniques to control the position of the lips and tongue, to highlight the volume of a particular overtone and suppress other overtones and fundamental tones. The Khoomei singers skilfully use the overtones to form different melodic patterns. The most significant difference between Khoomei and general singing is that the sound we hear produced by the singer's vocal cords during general singing is the melody sound, which means the fundamental tone itself is a melody. However, the pitch produced by the Khoomei singer's vocal cords is unchanged, the fundamental tone is a continuous and steady bass, and the overtones higher above will form the melody (see fig.1). The continuous low fundamental tone supports the melody formed by overtones, which sounds like a person singing two voices at the same time. Therefore, Khoomei is also known as the 'double tone singing.' The sound source of Khoomei is the through the vibration of the vocal cords, in the same way, if we change the source from the vocal cords to an elastic object, it will become an instrument that uses overtones. The instrument named Jew's harp has the same principle of producing sound as Khoomei.

fig.1 General Singing vs. Khoomei

Fundamental Tone

When a singer sings Khoomei, the low-frequency region of their vocal cord will produce an original low pitch sound, which is called a fundamental tone. A singer is required to control their breath through suppressing, squeezing and pushing up, breath out from the lungs, adjust the vocal cord when the breath is passing through the throat, and control the tones.

Whistle Voice

The most fantastic part of Khoomei is that it produces a whistle voice at the high-frequency region while singing the fundamental tone. From the perspective of vocal music, the method of breathing in Khoomei is relatively unique. This unique breathing method produces a whistle voice in the high-frequency region. Furthermore, it is also essential to adjust the resonance chamber of the human body. Often one is required to adjust the laryngeal cavity, pharyngeal cavity, and nasal cavity to produce whistle voice. There is also the beautification of the timbre, which also plays a role in the expansion of the whistle voice

Resonance Chamber        

The resonance organs of the human body mainly include the thoracic cavity, the oral cavity, and the head cavity. The thorax consists of the trachea, the bronchus, and the entire lungs below the larynx; the oral cavity includes the larynx, pharyngeal cavity, and mouth; the head cavity includes the nasal cavity, maxillary sinus, frontal sinus, sphenoidal sinus, so on. During singing, the tendency to use these resonators varies depending on the pitches. Generally speaking, when singing the low pitch, the resonance of the thoracic cavity plays the most significant part. When singing the alto, the application of the oral cavity will be more. When singing the high pitch, the head cavity will mainly play the role.

The vibration of the vocal cords purely produces the continuously low pitch voice, but the whistle voice with melody is a product of the sound of vibrating vocal cords in the process of audio mixing through the mouth. When the shape of the mouth and the position of the tongue changes, part of the voice be separated, and then form the whistle voice we hear by passing through the secondary resonance. The fundamental tone is produced by the vocal cords, and the overtones are produced by the reflection of different cavities in the head. The different pitches of the voice (frequency) can achieve by changing the space of various cavities by muscles, tongue, jaw, so on.

Vocal Cords

fig.2 The position of true vocal cords and false vocal cords.

The vocal cords are essential organs that produce voice. They are located in the middle section of the pharyngeal cavity, and they are composed of three parts which are the vocal cord muscle, the vocal ligament, and the mucous membrane. Vocal cords appear to be symmetrical in structure. The lamina propria is connective tissue, at the edge of the fold, there are durable elastic fibers and striated muscles, with excellent elasticity. The sagittal fissure between the two-zone is the rima glottidis. When producing a sound, the vocal cords on both sides are generally tightened, and the air flows continuously rushes into the vocal cords to vibrate then produce a sound. Both the length and tightness of vocal cords can affect the pitch of the sound. The false vocal cords locate at the top of the true vocal cords (see fig.2), these two pairs of vocal cords are parallel to each other. In our general talking and singing, the false vocal cords do not participate in the vocalization, because the two pieces of the false vocal cord are far apart from each other, which has no impact on the airflow. However, in overtone singing, false vocal cords play an essential role.

Mechanism

When singing whistle voice during Khoomei, the true vocal cords vibrate every time, the time it takes to open becomes shorter and the time it takes to close becomes longer, the gap between the false vocal cords is smaller, the vocal cords will constantly collide with the false vocal cords, and the true vocal cords will also violently collide with each other during each vibration. Therefore, the strong high- frequency overtones can be produced. After the vocal tract filter these high- frequency overtones, one of them will be highlighted and become the melody we hear. The lower the fundamental tone, the clearer the whistle voice, and the more pleasant the timbre.