THE VOICE 351 



a very loud sound, the great force of the air current causes 

 the vibrations of the vocal cords to be painful. 



630. The muscles of the larynx will grow strong by judicious prac- 

 tice, so that a person can be heard across a hall in which he formerly 

 could not be heard a few feet away. If the voice becomes husky, or 

 causes a cough, or if the throat begins to feel painful, the vocal cords 

 are being overworked and should be rested. 



631. Quality of the voice. A string stretched between 

 the hands produces a faint unpleasant sound ; but if it is 

 stretched over a hollow box, like the body of a violin, the 

 whole box will vibrate and greatly magnify the sound and 

 also will make it full and pleasant. 



The vibrations of the vocal cords alone produce a faint 

 and almost squeaking sound very unlike that of the voice ; 

 but below the larynx are the hollow trachea and lungs. 

 Above it are the hollow mouth, nose, and frontal sinuses. 

 All these vibrate with the vocal cords, and so the quality 

 of the voice is modified. Each person's voice has a peculiar 

 quality of its own which is at once recognized. 



When a person sings with the nose stopped, we say 

 that he sings through the nose. In reality, a nasal voice 

 is due to the absence of vibrations in the nose. 



632. Ventriloquism. The quality of sound is modified by 

 distance, so that one can judge accurately whence it comes. It is 

 possible to imitate the quality of distant sounds, so that there seems to 

 be another person talking in a remote part of the room or inside of the 

 real talker. This is called ventriloquism. 



633. Speech. Speaking consists mainly in rapid changes 

 in the quality and duration of vocal sounds. In singing or 

 crying out, single sounds are more or less prolonged, but 

 in forming spoken words, the sounds are cut off by the 

 tongue and lips several times a second. It is not even 

 necessary to form a sound with the larynx. In whispering, 



