th refer only to stuttering and stammering.

These forms of defective speech are manifested by the inability to
express words in the normal, natural manner--freely and fluently. In
other words, there is a marked departure from the normal in the methods
used by the stammerer in the production of speech. It is necessary,
therefore, before taking up the discussion of the causes of stuttering
and stammering, to determine the method by which voice is produced in
the normal individual, so that we can compare this normal production of
speech with the faulty method adopted by the stutterer or stammerer and
learn where the fault is and what is the cause of it.

Let us now proceed to do this: In other words, let us ask the question:
"How is speech produced in the normal person not afflicted with
defective utterance?"

Voice is produced by the vocal organs much in the same manner as sounds
are produced on a saxophone or clarinet, by forcing a current of air
through an aperture over which is a reed which vibrates with the
sounds. The low tones produced by the saxophone or clarinet result from
the enlargement of the aperture, while the higher tones are produced by
contracting the opening. Variations of pitch in the human voice are
also effected by elongation and contraction of the vocal cords with
comparative slackness or tension, as in the violin.

It would be of no value, and, in fact, would only serve to confuse the
layman, to know the duties or functions of the various organs or parts
entering into the production of speech. Suffice it to say that in the
"manufacture" of words, there are concerned the glottis, the larynx,
thorax, diaphragm, lungs, soft palate, tongue, teeth and lips. In the
production of the sounds and the combination of sounds that we call
words, each of these organs of speech has its own particular duty to
perform and the failure of any one of these organs properly to perform
that duty may result in defective utterance of some form.

BRAIN CONTROL: It must be borne in mind that for any one or all of the
organs of speech to become operative or to manifest any action, they
must be innervated or activated by impulses originating in the brain.

For instance, if it is necessary that the glottis be contracted to a
point which we will call "half-open" for the production of a certain
sound, the brain must first send a message to that organ before the
necessary movement can take place. In saying the word "you," for