Investigating The Voice

The voice follows the rules of physics… The pitch of a vocal sound is affected by the air pressure in the lungs, length and tension of vocal folds Vocal folds act like a “free reed”: the production of sound does not depend on feedback from an air column to determine the pitch Consider the analogy of air coming out of the stretched neck of a rubber balloon

Vibrato As found in Western art music (operatic style): undulation of the frequency and amplitude of partials Thought to be achieved with both laryngeal muscles and air flow Typical rate is 5-7 Hz.

Vocal Registers The voice does not “overblow” to sing in a higher register Female - “chest voice” is lower & fuller “head voice” is higher & lighter Male - “chest voice” is lower & fuller “falsetto” is higher and lighter Falsetto involves a different shape to vocal folds; perhaps not completely closing Countertenor: male singer specializing in falsetto register

Action of vocal folds Let’s take a look and see…. Show portions of part 4 of video series on the voice; regular camera, then strobe camera

Vocal Formants Formant: “a broad resonance region that enhances the upper harmonics lying in a fixed frequency range…” Roederer, p. 128 Think of a formant as a type of filter which boosts certain ranges of frequencies (and reduces others) from a sound generator Analogy to wooden box of a violin (even the same strings will sound different mounted on a different violin) V

Vocal tract acts like an air column which is closed at one end, with a length of approx. 14 cm (female) or 17 cm (male) An air column of 17 cm would produce a fundamental resonance around 550 Hz., with odd partials above that at 1650 Hz and 2750 Hz. (remember how waves act in a closed tube) These resonance points are formants

Vowel sounds Created by changing vocal tract to place formants (typically first and second formants) at different frequencies See following graph

The vocal tract is a flexible tube… With a wide pharynx, the larynx tube can act like a separate resonator and can be tuned to line up 3rd and 4th formants This can produce the “singer’s formant”, with a peak around 2500-3000 Hz. The singer’s formant is used especially by male singers and altos; the fundamental frequencies sung by sopranos make their overtones too high Singers making the most of formants in this range can be heard over a full orchestra (!) and in large spaces

The singer’s formant allows the singer to be heard over the orchestra (graph from Benade, Fundamentals of Musical Acoustics)

Overtone Singing Is it possible to sing more two or more notes at once??? Listen to Artii-Sayir (“The Far Side of a Dry Riverbed”) performed by Vasili Chazir

Overtone singing is 2, 3, or even 4 sounds at once Found in several cultures of inner Asia, such as Mongolia and southern Siberia Tuvan people of the Republic of Tyva have received attention in the last 10 years Overtone singing used to lull babies, herding, hunting, wedding celebrations

How is it done? Use a tone with a low fundamental frequency (< 100 Hz.) Manipulate shape of vocal tract to align the frequency of one or two formants (such as 1st and 2nd, or 2nd and 3rd) to a harmonic, thus enhancing it so that it is heard as a separate sound