y one may readily convince himself that resonant vocal sounds
can be produced only by a certain muscular effort additional to that
ordinarily needed. If after uttering a word in his speaking voice, the
reader, without changing the pitch or the loudness, will _sing_ this
word, he will perceive that before he can sing it, he has to alter the
adjustment of the vocal organs; to do which a certain force must be
used; and by putting his fingers on that external prominence marking the
top of the larynx, he will have further evidence that to produce a
sonorous tone the organs must be drawn out of their usual position.
Thus, then, the fact that the tones of excited feeling are more
vibratory than those of common conversation is another instance of the
connection between mental excitement and muscular excitement. The
speaking voice, the recitative voice, and the singing voice, severally
exemplify one general principle.

That the _pitch_ of the voice varies according to the action of the
vocal muscles scarcely needs saying. All know that the middle notes, in
which they converse, are made without any appreciable effort; and all
know that to make either very high or very low notes requires a
considerable effort. In either ascending or descending from the pitch of
ordinary speech, we are conscious of an increasing muscular strain,
which, at both extremes of the register, becomes positively painful.
Hence it follows from our general principle, that while indifference or
calmness will use the medium tones, the tones used during excitement
will be either above or below them; and will rise higher and higher, or
fall lower and lower, as the feelings grow stronger. This physiological
deduction we also find to be in harmony with familiar facts. The
habitual sufferer utters his complaints in a voice raised considerably
above the natural key; and agonising pain vents itself in either shrieks
or groans--in very high or very low notes. Beginning at his talking
pitch, the cry of the disappointed urchin grows more shrill as it grows
louder. The "Oh!" of astonishment or delight, begins several notes below
the middle voice, and descends still lower. Anger expresses itself in
high tones, or else in "curses not loud but _deep_." Deep tones, too,
are always used in uttering strong reproaches. Such an exclamation as
"Beware!" if made dramatically--that is, if made with a show of
feeling--must be many notes lower than ordinary. Further, we have groans
o