air,
issuing from the vocal cords as a tone. In other words, the tone is
supposed to consist of a stream of air, which can be voluntarily
directed in the mouth, and aimed at some precise point on the roof of
the mouth. This is an utter mistake.

There is no "column of vibrating air," or "stream of vocalized breath,"
in the mouth during tone-production. In the acoustic sense, the air in
the mouth-pharynx is still air, not air in a current. The only motion
which takes place in the air in this cavity is the oscillatory swing of
the air particles. To imagine the directing of air vibrations in the
mouth, as we direct a stream of water out of a hose, is absurd.

What then is the "forward tone"? There must be some reason for this
well-known effect of a perfectly produced voice,--the impression made on
the hearer that the tones are formed in the front of the mouth. There
ought also to be some way for the singer to learn to produce tones of
this character. A consideration of this feature of the vocal action is
reserved for Chapter IV of part III.

_Chest Resonance_

Who was originally responsible for the doctrine of chest resonance, it
would be impossible now to determine. Were it not for the fact of this
doctrine having received the support of eminent scientists (Holmes,
Mackenzie, Curtis, and many others), it might be looked upon as a mere
figure of speech. That the tones of the voice are reinforced by the
resonance of the air in the chest cavity, is an utter absurdity. In the
acoustic sense, the thorax is not a cavity at all. The thorax is filled
with the spongy tissue of the lungs, not to mention the heart. It is no
better adapted for air resonance than an ordinary spherical resonator
would be, if filled with wet sponges.

_Nasal Resonance_

Enough was said of the theories of nasal resonance in Chapter IV of Part
I to show the unscientific character of all these theories. It remains
only to point out the misconception of acoustic principles, contained in
all the discussions of the subject. This is very much the same as in
the theory of "forward emission," viz., that the tones of the voice
consist physically of a "stream of vocalized breath." The mistaken idea
is, that nasal resonance results from part or all of the expired breath
passing through the nose.

What is nasal resonance? How is it caused? What is its effect on the
tones of the voice? These questions have never been answered. It can
however be proved that