Kashudo (歌手道): Resonance and the released jaw

The idea of the “natural voice” is so froth with contradiction that it is almost foolhardy to address the many issues that contribute to the confusion. But that is the point of this blog: making sense of misconceptions and confusions. One of the issues that I find troublesome in the current pedagogy environment is the idea of singing with a closed mouth or nearly closed to be exact.

There is a reason why most vocalises are done of the [a] vowel and that most dramatic high notes are written on the [a] vowel. The baby’s cry is produced on a vowel that fall on or near the [a] vowel spectrum. Both the dramatic high note and the baby’s cry are meant to attract attention. They are both meant to be acoustically piercing; the high note piercing the orchestral texture and the baby’s cry piercing through ambient noise and the lulling dullness of their parents’ slumber.
The released jaw, consistent with a good [a] vowel releases the larynx to a lower position.
With the jaw closed touch the surface of the larynx at the thyroid cartilage (Adam’s apple)
and while touching it release the jaw. The larynx automatically goes slightly lower.
The released jaw also promotes a palatal stretch without additional muscular activity. So why do many teachers promote the idea of a closed jaw or at least a closed mouth?
A well phonated tone produces important high harmonics that contribute to audibility and vowel intelligibility. Indeed those overtones are not possible if the tone is not properly phonated. In the case of improper phonation (breathy or pressed), those high overtones are not very strong. The resultant sound is then dull. To give the illusion of a “brighter” sound (not necessary a resonant sound) the singer will reduce the low harmonics. The easiest way to do this is closing the jaw, which brings the larynx up with it, thereby reducing the strength of the lower harmonics.
Another reasoning is adherence to the Italian axiom, “si canta come si parla” (one sings as s/he speaks). There is a problem with the axiom itself (already discussed on the blog). We do not speak with the intent of piercing through orchestral textures or our parent’s lulling sleep, except as baby’s and at parties. In other words, every day speech does not require peak acoustic output. This is particularly relevant to the production of the [i] vowel. Most of us produce an [i] with the jaw closed because it is easier to coordinate. The tongue, principal muscle of vowel formation does not need to be very active to produce an [i] when the jaw is closed. With the jaw released in the [a] position, the back of the tongue has to migrate considerably to form the [i] vowel. This is not easy for most singers. To make matters worse, the natural acoustics of the [i] vowel yield strong high partials even when the jaw is closed. Therefore there is little insentive to produce an [i] with the released jaw.
My argument is the following. The [i] vowel can yield strong high partials even when phonation is not ideal. In fact, when phonation is unbalanced, singing a closed jaw [i] vowel produces an acceptable sound. If however the jaw is released, the sound even on [i] often becomes dull. This can be confused to mean that a released jaw yields a dull sound. And this is precisely the conclusion that many teachers come to. However it is the opposite. What the release jaw does is that it reveals the nature of the phonation. If the phonation is breathy or pressed, when the jaw is released, the sound will be of poor quality. Therefore by maintaining a released jaw, we are able to uncover the inefficiency and then are required to address it. When the inefficienty is addressed, then good phonation will be the norm and be able to transfer from one vowel to the next without loss of quality.
The previous paragraph alludes to a common problem that is often discussed of discussion forums: “why is it that when I transition from [i] to [a], the [a] falls in my throat?” Because the [a] vowel requires a released jaw, the inefficiency inherent in the closed jaw [i] manifests when the jaw is released on [a].
Beyond revealing the glottal inefficiency, the released jaw makes for a better acoustical environment for vocal production. The lower laryngeal position is absolutely crucial to the operatic production (less so for Commercial Contemporary Music). A lower larynx (not depressed, but rather released when the jaw is released) promotes strong first formant resonance and gives strength to lower notes. The first formant also helps in the transition to the female middle voice and the male high voice. By maintaining the integrity of the first formant, as pitch rises, the dominance of the first formant is left behind and the influence of the second formant takes over. If however the larynx climbs (research shows that first formant values rise when the larynx rises) then the first formant will continue to follow the rising pitch and the acoustic transition from low register to high (middle for women) does not occur. Instead there would be a conflict for dominance between the two formants and the sung tone would be unstable. In fact this is the central argument for a double formant strategy. Not that both formants dominate, but that in order for one formant to dominate when it is appropriate, the other formant must not interfere.
If the larynx rises we also lose the efficiency in phonation provided by supra-glottal inertial reactance.
Each singer behaves differently and some very skilled singers are able to produce a very satisfying sound with a closed jaw. However, resonance is often weakened in a certain area of the range. Clever singers often preempt the loss of power by making an adjustment before the problems occur (e.g. bringing the chest voice higher, letting the larynx climb really high, etc). We are also willing to accept a certain loss of quality in parts of the range when the singer sings extraordinarily in the top voice. Such singers are often cited as examples of successfully singing with a closed jaw. It is crucial to give singers credit for their strengths and not for their weaknesses. A great singer can be great because of awesome stage presence, refined musicality, a strong vocal output, even while leaving much to be desired technically.
By following correct acoustic principles, it makes sense to maintain a released position on all vowels and to return to the released position after articulating consonants that require closure (fricatives in particular). Maintaining a flexibly released jaw promotes consistency in the resonance of the sound and gives an even quality from vowel to vowel. This is not easy to accomplish and requires a level of patience. When accomplished, this release reveals technical flaws that can then be addressed yielding a vocal instrument capable of maintaining stability thorugh the many changes required by the operatic repertoire.
I wish to pay tribute to Daniel Pratt, one of my early teachers who emphasized the importance of what he called “the tall [i]”. Great principles stay with us through all our different stages of development.

© 07/18/2009