3. Phonation

Phonation is the process of generating acoustical energy at the level of the larynx. This energy is the result of the vibratory activity of the vocal cords, two elastic muscular bands which form the edges of the thro-arytenoid musculature. They are attached to the inside of the thyroid cartilage (Adam's apple) in front, and to the arytenoid cartilages in the back. The average length of these cords is about . 7 of an inch in the male changed voice and about . 4 of an inch in the female voice. When they are in a healthy condition the vocal cords are slate gray in color; when they are not, the vocal cords are light or white in color, pink and even bloodshot.

Two theoriesr31 have been advanced to explain the function of the vocal cords in the process of phonation, the puff theory and the harmonic theory. According to the puff theory, the vocal cords give off puffs of sound which are amplified or modified by the resonators above. According to the har­monic theory, the vocal cords give off complex sound waves which are com­posed of fundamentals and a rich supply of overtones.

Motion pictures of the vocal cords taken with only one sound and one in­tensity in order to give a clear picture of the larynx, lead one to the conclusion that the vocal cords vibrate much in the same way for all vowel sounds and all intensities32 This would be essentially the puff theory. As a matter of fact the larynx and the vocal cords themselves change in shape, and the epiglottis changes in position depending on the vowel and the intensity sung. This would lead to the conclusion that the complete acoustical picture is dependent on more than just puffs of sound. This would be the harmonic theory. For the most part authorities agree that phonation is a combination of both.

It has been mentioned before that changes in the articulatory mechanism are reflected in the larynx, the vocal cords, and the epiglottis. The theory has been advanced that phonation maybe considered as a part of articulation. Primary enunciation of the vowel sounds or voice would then be at the level of the larynx or voice box, as it has been called. Secondary enunciation and articulation or speech would be at the level of the mouth.

Since the action of the larynx, the vocal cords and the epiglottis are be­low the level of consciousness33 there is only one way in which the teacher can tell whether the proper co-ordination of articulation and phonation has been accomplished. That is by the way the voice sounds. When properly produced, the singing voice has a satisfying quality, a psychological effect of being free. Interferences, such as undue tension of the tongue, the soft palate, the lips, the pharynx, and the lower jaw, will be transmitted to the larynx and will prevent unhindered vibrations of the vocal cords, thereby changing the sound spectrum on which good quality is dependent.

Poor posture, particularly of the head with the chin pulled down de­pressing the larynx, or with the chin tilted up raising the larynx, changes the tone quality. Laryngeal position may be used as an index of quality: a high position results in nasality, a low position in a guttural or muffled qua­lity, and a middle position in normal quality.

Practically all books on singing, in one way or another, acknowledge registration, or the existence of registers. The more common terminology includes such terms as the chest and head voice, in women, the chest and falsetto voice, in men; the thick and thin registers, the heavy and light registers, and the low and high voice mechanisms. Defined, a register is a series of tones of like quality produced by a particular adjustment of the vocal cordsw It is often argued that there are no such things as registers, or that each tone is in itself a register, or that when the voice is properly produced there are no registers. Science, however, makes use of the term­inology and proves through research in neurology and research in laryngeal photography that changes in quality are actually due to readjustments in po­sition of the vocal cords. The singer who cannot handle his registration properly, whether he understands it scientifically or not, is certainly at a disadvantage in making use of his complete singing range.

Let us say that the average normal individual with vocal talent has a potential range of at least two octaves above the average normal pitch of his speaking voice. About an octave above his speaking pitch, when vocalizing on the sound ah, there is a change in registration which is called by some teachers "the first lift." This may be called the end of the chest voice and the beginning of what may be called the middle voice or mixed voice.

This encompasses about a fourth or fifth, and changes to what might be called "the second lift." This is the beginning of the high voice register, in male voices called the falsetto mechanism, and in female voices the head voice. The length of this register should be at least a third or a fourth.. The pattern for registration, then, is essentially a low voice of an octave, a middle or mixed voice of a fourth or fifth, and a high voice of a third or fourth. The so-called "lifts" may be described as changes in resonance placement.

The teacher's problem is to smooth out or blend these registers so that the changes from one to the other are not obvious. The best approach is through open tone or open vowel singing, and teaching the student how to make or allow changes in resonance placement.

In men's voices these changes seem too obvious in the beginning, and most students cannot believe that this is the correct technique. This is be­cause there must be changes in resonance placement to bring about changes in the vocal cord adjustments without releasing the basic vocal cord tension. These changes in resonance placement cause modifications in the resonance quality, in the vowel sounds, and in the tactile or placement sensations.

The production of acoustical energy in terms of vocal sound is the result of tensions - the tensions of the vocal cords resisting a pressure flow of the breath caused by the tensions of the abdominal and intercostal muscles. The production of a singing speech or diction, although psychologically induced, is the result of tensions of the articulatory mechanism which is constantly changing, and as a result changing the resonators.

There must be however a flexible basic tension of the vocal cords which is reflected in the vowel sounds as normal quality. This is a matter of learn­ing to tune the resonators to the phonation process without losing control of the basic tension. The practice of singing a messa di voce - singing a tone on one pitch from pianissimo to fortissimo and back to pianissimo - will illustrate whether the basic tension is present. Without it the singer will find it difficult to swell the tone. If the tension is too tight, flexibility of the voice is lost.

Many contraltos and basses overdo the use of mouth resonance and the use of the lips in the lower and middle ranges, thereby releasing the basic vowel tension in the larynx to the point where control of normal quality is lost. The tone may be large but lacking in vitality and clarity of diction. From an acoustical standpoint there is an overemphasis of the low formant. In the case of sopranos and tenors the basic vowel tension may be too tight, resulting in a brilliant metallic tone lacking in mellowness and beauty. This is due to overemphasis of pharyngeal or throat action, resulting in over­emphasis of the high formant.

Are You Ready To Move Onto The Next Lesson? Click Here...