1. Fully pronounce the word hung (u as in stung) at once, and prolong the tone, not on the vowel sound but on the ng sound. This establishes the proper head and nasal resonance at the very beginning of the exercise.
2. In passing from ng to ee be very careful not to change the initial focus or lose the sensation of nasal and head resonance. Do not therefore move the lips or the chin. The only change at this point is the slight movement of the tongue required to pronounce ee, which must be a pure vowel without a trace of the preceding g.
3. In passing from ee to oo, from oo to oh, and so on, do so with the least possible movement of lips and chin. The initial sensation of nasal and head resonance must not be lost.
4. Each vowel sound must be distinct in enunciation and pure in quality. Avoid blurring one with the other. Give each its true individuality.
5. As jewels of different hue hung on a string, so must this exercise be the stringing of vowels on a continuous stream of sound.
[Exercise I]
TO ESTABLISH NASAL AND HEAD RESONANCE
This is an exercise for focusing or placing the voice and developing the vibrations of the nasal and head cavities, the most essential parts of the resonant apparatus. If the nostrils are kept fully open, no nasal twang will be heard. The strength of the tone will correspond to the force of the vibrations of the nose and head, which can be plainly felt by resting the finger lightly upon the side of the nose. The vibrations may eventually be plainly felt on the top and back of the head.
Attack, that is, begin the tone, softly and on no account force it in the least. Pronounce the full word at once, prolong the ng four counts as indicated, and sing the five vowel sounds on a continuous, unbroken tone. Articulate entirely with the lips and without moving the under jaw. In this, as in the following exercises, keep the under jaw relaxed and open the mouth so as to separate the teeth as wide apart as is consistent with the action of the lips. See also the illustrations of proper lip position given at the close of [Chapter II].
Practice this exercise on any pitch easy for the voice.