SOURCE-F ILTER THEORY IN TUVAN THROAT S INGING

PHYSICS 1204 – DR. SELBYJasmine Edison

Image courtesy of http://www.alashensemble.com/tuva_map.htm.

TUVA AND THE TUVINIANS: AN INTRODUCTION

When the average Westerner hears the words “Tuvan throat singing”, they are

completely ignorant of their meaning. A select few might have some idea based on

various references in popular culture, such as the television show The Big Bang Theory,

in which one of the characters laments the renunciation of his dream to master the

technique (Season 3, episode 15). Others might have gained exposure via the concert hall,

attending performances by ensembles like Alash who are making their international

rounds as throat singing gains popularity with global audiences

(http://www.alashensemble.com/index.htm), and even those enlightened people may not

understand the cultural background or the physics behind this fascinating technique.

These topics will be the main focus of this paper in the hopes that the reader develops a

familiarity with, and perhaps a fondness for, the art of Tuvan throat singing as well as the

people and the culture with which it is inextricably linked.

In order to gain a familiarity with Tuvan throat singing, it is important to know what

and where Tuva is. Tuva is an autonomous republic in the heart of Asia

(http://www.alashensemble.com/about_alash.htm). Tuva has spent most of its existence

under the banner of larger empires, from Mongolia to China, then Russia in its imperial

and revolution-era forms, eventually joining the USSR in 1944, and then becoming an

Autonomous Republic in 1961 (Granville, 1). Tuva is currently part of the Russian

Federation. It lies northwest of Mongolia, the country with which Tuvan throat singing is

most often mistakenly associated, and is nested at the very bottom of what Westerners

know as Siberia (Granville, 1). Since the vast majority of the population consists of

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ethnic Tuvinians—no less than sixty-four percent—this area has a rich cultural heritage,

most prominently displayed by the unique musical tradition that will be discussed in

detail over the course of this paper (Granville, 1).

TUVA: THE MUSICAL TRADITION

The music of Tuva is interwoven with the spiritual beliefs of the people, their

surroundings, and their oral tradition, which means that Tuvan throat singing is as much

an impressive display of the acoustic capabilities of the human voice as it is an

expression of these tightly interwoven aspects of Tuvan culture. One such aspect is

Tuva’s strong tradition of animism, or the belief that natural objects—from mountains to

rivers and trees—are endowed with or inhabited by spirits. Adherents to animism believe

that these objects manifest their spirituality through their location, their physical shape,

and most important for our purposes, the sounds that they make (Levin and Edgerton,

80). According to legend, it is these sounds that the first throat singers tried to mimic

when they learned their craft. They wished to imitate the timbres of the natural world, to

sound like rivers, lakes, mountains, and various other objects found in nature (Levin and

Edgerton, 80).

Any person who has been outdoors knows that the sounds of nature are not the

simplest to reproduce using only the human voice. The gurgling sound of a babbling

brook lies far beyond the reach of the average human vocal range, and the low notes of

the male throat singers are on par with those of the most highly trained operatic basses1.

1 The extreme bass range in the standard operatic repertoire bottoms out at around 65.4Hz, or C2, the C two octaves below middle C, or below the bass staff (Levin and Edgerton, 82).

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Producing either sound is a daunting task, but Tuvan throat singers manage to produce

both simultaneously.

Throat singers accomplish this impressive feat through clever manipulation of their

bodies, specifically the vocal folds and the oral cavity, as well as an informal knowledge

of musical gestures. This technique is not formally taught, but picked up by farmers and

nomadic herders, and passed down orally to future generations. Before the arrival of

Russians, most Tuvinians were illiterate, which resulted in the rich oral and musical

tradition that continues to preserve this technique (Granville, 1): a significant portion of

the rural male population can throat-sing (Levin and Edgerton, 82), and although a taboo

exists for females2, it is slowly being lifted as more female throat-singers emerge, some

of whom have formed bands, like the Tyvakyzy (“Daughters of Tuva”), the first

professional female throat-singing group (http://tyvakyzy.com/).

Informal though it may be, there are some aspects of music theory that must be

addressed when discussing throat singing. One aspect in particular is the avoidance of

certain notes in the higher registers to maintain a consistent scale. Levin and Edgerton

noticed this phenomenon when they first encountered Tuvan throat singing:

“In the seven-note scale between the 6th and 12th harmonics—the segment of the spectrum used by Tuva and Mongolian singers—performers scrupulously avoid the 7th and 11th harmonics because the local musical syntax favors pentatonic melodies, like that of the hymn ‘Amazing Grace3’” (Levin and Edgerton, 8).

In other words, the singers are only choosing five notes out of the seven that are

available in a typical seven-note C major scale, which consists of C-D-E-F-G-A-B-C. In

the pentatonic, or five-note, scale, the fourth note, F, and the seventh note, B, are missing.

2 The taboo surrounds fertility, and the fear that if a woman practices throat singing in public, she will be infertile (Levin and Edgerton, 82).3 http://www.youtube.com/watch?v=nPu9XMMY1Y8: In this video, Nestor Kornblum demonstrates both throat singing and the pentatonic scale in his performance of Amazing Grace.

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Since the local musical tradition does not favor those notes, throat singers skip over them

when creating their melodies.

Image courtesy of Stefan Kostka. Materials and Techniques of 20th Century Music (p. 38)

THE SOURCE AND THE FILTER:

VOCAL ACOUSTICS OF THROAT SINGING

Before an aspiring throat singer even approaches the point of musical creation,

they must first learn how to control their vocal folds and oral cavities to produce the

proper sounds. The vocal folds, the “source” of human sound production, are the small

flaps of muscle that allow humans,

and other animals with similar

anatomy to generate sounds. As

shown in the image to the left, the

vocal folds are found in the throat,

just below the epiglottis, the flap

that opens when food is swallowed

(image courtesy of Bickford &

Tuggy, SIL.org). The vocal folds are

left open when breathing so that air may pass form the lungs to the mouth and nasal

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cavity uninterrupted, but when humans speak, sing, or make other sounds with their

mouths, the folds open and close rapidly, releasing air up through the rest of the vocal

tract and out of the mouth (Levin and Edgerton, 82). The frequency at which the folds

vibrate determines the pitch of the sound produced, but the air must also pass through

various obstacles, such as the teeth, the tongue, and the lips. These obstacles form the

sound filter. In order to make musical sounds—and even speech, humans use the various

parts of the filter in order to highlight specific parts of the overall sound that is generated

by the source (Tilsen, 2012).

Any given sound made by the human voice has several components: the

fundamental frequency, which is directly related to the number of times per second that

the vocal folds vibrate, and the integer multiples of that frequency, or harmonics, which

together make up a harmonic series of frequencies. The human ear interprets the whole

series as one frequency that has the same pitch as the fundamental (Mannell, 2008). In

Tuvan throat singing, their presence is made abundantly clear with the ingenious

manipulation of the filter.

Below is an illustration of the harmonic series, based on a fundamental frequency

of 65.4Hz, or C2, the lowest extreme in most standard operatic repertoire. Notice how the

pitches are closer together as the range becomes higher. It is this compression in the

upper harmonics that allows throat singers to generate stepwise melodies.

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Image courtesy of khoomei.com

FORMANTS

Another important part of the acoustics of throat singing is the formant, or the

resonance frequency of a vocal sound. The image below demonstrates both a

harmonic series (in red) and the resonance frequencies or formants (in black). The

vibrations of the vocal folds determine the fundamental frequency of this spectrum,

while the position of the other parts of the vocal tract, particularly the tongue,

determine the location of the formants.

Image courtesy of Prof. Tilsen, 2012.

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Formants are important to throat singing because they are the source of the

melody that gives the technique its distinction. A throat singer can hum a drone at a

specific frequency, and then adjust his vocal tract to amplify certain resonance

frequencies, and if he is successful, both the drone and the chosen formants will be

heard. The chart below demonstrates this phenomenon. The Source Spectrum is the

harmonic series that would appear if a sound was made with only the vocal folds and

no interruption from the filter system in the vocal tract. The resonance frequencies are

those that the vocal tract amplifies best, and when combined, the old spectrum has

contains frequencies that would have otherwise gone unnoticed without a filter.

Image courtesy of Prof. Tilsen, 2012.

In human speech, this sort of spectrum would be common for vowel sounds, since

they have definite frequencies and are highly affected by the position of the vocal

tract. Formant locations would shift when vowels shifted, hence the concept of lighter

and darker vowels. For example, the vowel [i]—pronounced “ee” as in “see”—is a

brighter vowel than the vowel—[u]—pronounced “oo” as in “soon”. The position of

the vocal tract would amplify higher frequencies for [i] than for [u].

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Throat singers also shift formants, but their vocal folds close more rapidly and for

longer periods of time than they would under normal speech circumstances, resulting

in a more efficient filter than that for normal speech (Levin and Edgerton, 84). Faster

closing time results in greater outward pressure from the source and thus better sound

projection. Longer duration of vocal fold closure results in less extraneous air coming

moving through the vocal cavity and thus clearer formants. In addition to the efficient

movement of air, the singers are also deft at adjusting their oral cavities, which, when

combined with the previous techniques, allows them to project their chosen formants

above the others, which creates the melodies we hear.

CASE STUDY: THE KARGYRAA STYLE

The kargyraa style of throat singing takes Tuvan throat singing to a higher level of

complexity by introducing an entire octave below the one used in other styles. Such low

bass notes, typically the domain of the Russian Bass, can also be achieved by the Tuvan

throat singer, who makes use of extra organs, particularly the ‘false folds’, which remain

unmapped on the Vocal Tract diagram in the previous pages. The false folds are aptly

named for their position and similarity in function to the true vocal folds (Levin and

Edgerton, 86).

Like the true vocal folds, the false folds open and close the passage between the lungs

and the oral cavity, but since the false folds are above the true, they can shorten the

length of the vocal tract, and thus raise the frequency of their melodic formants. They

make up for their frequency shifts, however, because they vibrate at half the frequency of

the true folds, which translates into a downward leap of a full octave. The false folds

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render an already efficient vocalizing machine even more so, which makes the octave-

dropping effect they produce all the more impressive.

The kargyraa style is unique among an already uncommon technique. The use of the

vocal tract to create simultaneous melodies and stretch the limits of the human voice

provides a fascinating window into the possible links between physics and music. Tuvan

throat singers have pushed the limits of possibility in the acoustic sciences, the

implications for musicological, linguistic, ethnographic, and physics research of this

fascinating technique are vast, but every effort must be made to preserve the culture from

which this impressive technique has come. There are a myriad of ways one can study this

technique, but the most important is through experience. I have attempted throat singing,

and although I was unsuccessful, I learned a great deal about what it really takes. Proper

placement of the vocal tract is important; choosing the right fundamental frequency for a

drone is also important, but the best way to truly grasp this fascinating art form is to close

the textbook, find an expert, and allow them to orally pass it onto you as it has been

passed on to countless Tuvans before.

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BIBLIOGRAPHY

1. GRANVILLE, JOHANNA. “Tuva and Tuvinians.” Encyclopaedia of Russian

History. Ed. James R. Millar. Vol. 4. New York: Macmillan Reference USA,

2004. 1593-1594. Gale Virtual Reference Library. Web. 9 May 2013.

2. Levin, Theodore, and Michael Edgerton. "The Throat Singers of Tuva." Scientific

American. 281.3 (1999): 80 - 87. Web. 12 Apr. 2013.

<1.http://www.nature.com/scientificamerican/journal/v281/n3/pdf/scientificameri

can0999-80.pdf>.

3. Kostka, Stefan. Materials and Techniques of Twentieth-Century Music. 3rd ed.

New Jersey: Pearson Education, Inc., 2006. PDF.

4. Kornblum, Nestor. Amazing Grace with Overtone Chant. 2009. Video.

Youtube.com. Web. 10 May 2013. http://www.youtube.com/watch?

v=nPu9XMMY1Y8.

5. Bickford, J. A., & Tuggy, D. (2005). The Principle Organs of Articulation.

Retrieved from http://www-01.sil.org/mexico/ling/glosario/e005bi-organsart.htm.

6. Alash: The Best New-Old Music from Tuva. N.p., n.d. Web. 12 Apr 2013.

http://www.alashensemble.com/index.htm.

7. Dostay, Otkun. (2006). Female Throat Singing. Retrieved from

http://tyvakyzy.com/.

8. Tilsen, S. (2012). Acoustic Phonetics. Unpublished manuscript, Linguistics,

Cornell University, Ithaca, NY.

9. Mannell, R. (2008, December). Source-Filter Theory of Speech Production.

Retrieved from

http://clas.mq.edu.au/acoustics/frequency/source_filter.html&strip=1

10. (2003, December 28). Harmonic Series [Web Photo]. Retrieved from

http://khoomei.com/pics/harmonic.gif

11. Fessenden, M. (2011, December 9). ‘Vocal Fry’ Creeping Into U.S. Speech.

Retrieved from http://news.sciencemag.org/sciencenow/2011/12/vocal-fry-

creeping-into-us-speec.html.

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