| | From: "Lloyd W. Hanson" <lloyd.hanson@n...>
Date: Sat Dec 14, 2002 6:56 am
Subject: Re: [vocalist] Two Chest Voices, wasChest to Mix, was Re: Too Many Low Notes
| Dear john and Vocalisters:
Your comments about the chest voice muscles and the head voice
muscles are not correct. I could go into some details with you about
this but at this point is is perhaps best to emphasize that it is
the vocal folds which produce the oscillation that is the driver for
a phonated tone (a tone as it emerges from the larynx) and it is the
quality of this phonated tone that is the source sound material out
of which the final resonated vocal sound is created through resonance.
The muscles that close the vocal folds (adduction) are the arytenoid
muscles as they pivot the arytenoid cartilages and the vocal folds
which are attached to them, into a closed position which is necessary
for phonation. The degree of closure determines the quality of the
phonated sound. A partial closure will produce a more breathy
phonated tone or, if the vocal folds are long enough as in the male
voice, a falsetto tone. A complete closure that is achieved as the
result of correct pre-phonatory tuning will produce a balanced
phonated tone that is rich in the correct harmonic spectrum. A
complete closure that has an excessive degree of medial tension
across the vocal folds will produce a pressed tone that sounds overly
tense and contains some harmonic spectrum that is not natural for the
fundamental being phonated. Only the second example given above ( A
complete closure that is achieved as the result of correct
pre-phonatory tuning) displays the maximum quality potential of the
individual voice.
The cricothyroid muscles are basically stretching muscles that
lengthen the vocal folds and, in so doing, increase the longitudinal
tension along the folds. The cricothyroid muscles achieve this
lengthening of the vocal folds by contracting and thereby pulling the
lower posterior of the thyroid cartilage toward the posterior of the
cricothyroid cartilage.
Neither the arytenoid nor the cricothyroid muscles come in direct
contact with the vocal folds themselves. They act only on the
cartilages to which the vocal folds are attached. Therefore it is
not possible for either of these muscles to be solely the chest
voice muscles or head voice muscles. The arytenoid muscles only are
involved in closure of the vocal folds and the cricothyroid muscles
are only involved in the stretching of the vocal folds.
Because a complete, balanced closure of the vocal folds is usually
considered the most desirable posture for maximum efficiency in
phonation, once this condition is achieved the arytenoid muscles have
no more effect on the phonated tone except to maintain that ideal
closure position.
However, as the cricothyroid muscles stretch and lengthen the vocal
folds the folds began to thin along their longitudinal edges and are
thus capable of oscillating more quickly which, in turn, produces a
phonated tone of higher and higher pitch. Chest voice is nothing
more than short fat vocal folds which tend to oscillate more slowly
because of their increased mass. Head voice is nothing more than
longer, thinner vocal folds which oscillate more quickly because of
their reduced mass. There is also some degree of damping of the
vocal folds, that is, reducing or eliminating oscillation of a
portion of the folds for the highest notes and this damping is
partially induced by a tipping of the arytenoid cartilages toward the
center of the glottis. It is believed that the arytenoid muscles
have some responsibility for this tipping action. Such damping does
not occur in all voices.
Falsetto is simply an incomplete oscillation of the lengthened vocal
folds which occurs because the vocal folds are not in complete
closure or adduction and are, therefore, less efficient. Only the
very edges of the vocal folds are set in oscillation (the mucosal
membrane) and their very slight mass produces a tone that is lacking
in the harmonic spectrum that would normally be present. Falsetto,
therefore, is not a form of head voice. Head voice requires a
complete closure of the vocal folds.
Going from falsetto into head voice is an extremely difficult
procedure for most singers. It requires that the partially adducted
vocal folds be completely adducted in a correctly balanced manner.
This degree of control of vocal function can only be achieved with
special exercises and a rather long training period.
Mixing chest voice with head voice in some arrangement or other is
often spoken of on this list but the reality is that the voice is
merely in transition from thicker vocal folds to thinner folds. One
cannot be in a thick folds conformation and, at the same time, be in
a thinner vocal fold configuration. In that sense it is not possible
to mix chest voice and head voice. But it is possible to be singing
a given pitch, say in the upper middle of the vocal range, in a
variety of conformations such as with slightly thicker vocal folds
(chest voice sounding) or slightly thinner vocal folds (head voice
sounding). But each configuration of the vocal folds in this example
is unique and they are not mixtures of each other.
--
Lloyd W. Hanson
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