It will be noticed that there is no difference in the breathing outline between these subjects.

The female subject, though a good singer, had had no training in breathing.

She previously insisted that she used only the chest breathing, and did not use the abdominal muscles, but actual test revealed the condition to be that shown in Figure 11 and convinced her that she was mistaken.
[Illustration: FIGURE 9.] [Illustration: FIGURE 10.] [Illustration: FIGURE 11.] [Illustration: FIGURE 12.] It is not unlikely that many other singers who now think they are using only the high chest respiration would, if subjected to the same test, find themselves similarly mistaken.
The contraction incident to forced expiration is much more tense than the enlargement of forced inspiration.

When singing or speaking, forced inspiration is not used.

Experience shows that the change in size of the body during speaking or singing is usually small.
Occasionally, long passages in music demand that the expulsive power of the breathing apparatus be used to its limit.
ECONOMY OF BREATH The quantity of air taken in with a single inspiration is, in quiet breathing, according to Prof.Mills,[3] from twenty to thirty cubic inches, but this may be increased in the deepest inspiration to about one hundred cubic inches.