.

A distinct fault of production, the tremolo, is directly due to throat
stiffness. A simple experiment illustrates the nature of the muscular
action from which the tremolo results. "Set" the muscles of the arm by
contracting the biceps and triceps with the utmost possible strength.
With the arm in this stiffened condition flex and extend the forearm
slowly several times. You will notice a pronounced trembling of the arm.
Why a condition of muscular stiffness should cause the affected member
to tremble is not well understood. But the fact admits of no question.
It is highly probable that the tremolo is caused by a trembling of the
vocal organs, due to muscular stiffness. The tones of a voice afflicted
with tremolo always give evidence of extreme throat tension.

Another bad result of throat stiffness in tone-production is seen in the
matter of intonation. Tones produced with a stiff throat are seldom in
perfect tune. This subject will be more fully treated in a later
chapter.

_Effects of Muscular Stiffness on the Throat_

Many of the muscles of the vocal organs, particularly the laryngeal
muscles, are extremely small and delicate. Under normal conditions these
muscles are fully capable of exerting the relatively small amount of
strength required of them without strain or injury. But when the voice
is used in a stiffened condition the delicate muscles of the larynx are
obliged to contract with much more than their normal strength. To borrow
an expression of the engineers, the throat muscles are then forced to
carry an excessive load.

A balanced contraction of antagonist groups of muscles is the muscular
basis of throat stiffness. When the voice is used in this condition each
muscle of the vocal organs must put forth the amount of effort necessary
to produce the desired effect under normal conditions, in addition to an
effort equal to the counterbalancing pull of its antagonist muscle. An
increase in the degree of throat stiffness demands a corresponding
increase in the effort exerted by every muscle of the throat.

Over-exertion of muscles always results in strain and injury. The extent
of the injury to the muscular tissues varies with the degree of
excessive exertion and with the duration of the injurious exercise. An
advanced stage of muscular strain is distinctly a pathological
condition.

Tone-production in a state of throat stiffness is of necessity injurious
to the muscles of the vocal organs. The delica