expended in setting the vocal cords in motion. No
energy of condensation is left in the expired air the instant it has
passed the vocal cords. Beyond that point there is no expiratory
pressure.

In one sense it is true that the expiration is "controlled" in
tone-production. But this control is strictly an automatic action. The
vocal cords are adjusted, by the appropriate muscular contractions, to
move in response to the air pressure exerted against them. This action
involves, as a necessary consequence, the holding back by the vocal
cords of the out-rushing air. So long as the vocal cords remain in the
position for producing tone, they also control the expiration. In this
sense breath-control is an inseparable feature of tone-production.

All that need be known of the mechanics of the voice is therefore
perfectly plain. The vocal cords are set in motion by the pressure
against them of the expired breath. This operation is in accordance with
Pascal's law and the law of the conservation of energy.

But this analysis throws no light on the nature of the correct vocal
action. It is impossible for the voice to produce a sound in any way
other than that just described. In speaking or in singing, in laughing
or in crying, in every sound produced by the action of the vocal cords,
the mechanical principle is always the same. Nor is the bearing of this
law limited to the human voice. Every singing bird, every animal whose
vocal mechanism consists of lungs and larynx, illustrates the same
mechanical principle of vocal action.

Only passing mention is required of the fallacy of the breath-band
theory. The idea of any necessity of relieving the vocal cords of the
expiratory pressure is purely fanciful. How any one with even a slight
understanding of mechanics could imagine the checking of the breath by
the inflation of the ventricles of Morgagni, is hard to conceive.

_The Psychology of Tone-Production_

This subject was treated, in some detail, in Chapter V of Part II. In
that chapter however we were concerned more with a destructive criticism
of the idea of mechanical tone-production than with the positive
features of vocal psychology. At the risk of some repetition it is
therefore advisable here to sum up the laws of psychology bearing on the
vocal action.

Considered as a psychological process, tone-production in singing
involves three distinct operations. First, the mental ear conceives a
tone of definite pitch, qualit