CHAPTER XXXVI. 



VOICE AND SPEECH. 



Voice consists of sounds produced by the vibrations of 

 two elastic bands, the true vocal cords, placed in the larynx, 

 an upper modified portion of the passage which leads from 

 the pharynx to the lungs. When the vocal cords are put 

 in a certain position, air driven past them sets them in 

 periodic vibration, and they emit a musical note; the 

 lungs and respiratory muscles are, therefore, accessory 

 parts of the vocal apparatus: the strength of the blast pro- 

 duced by them determines the loudness of the voice. The 

 larynx itself is the essential voice-organ: its size primarily 

 determines the pitch of the voice, which is lower the longer 

 the vocal cords; and, hence, shrill in children, and usually 

 higher pitched in women than in men; the male larynx grows 

 rapidly at commencing manhood, causing the change com- 

 monly known as the " breaking of the voice." Every voice, 

 Tvhile its general pitch is dependent on the length of the 

 vocal cords, has, however, a certain range, within limits 

 "which determine whether it shall be soprano, mezzo-soprano, 

 .alto, tenor, baritone, or bass. This variety is produced by 

 muscles within the larynx which alter the tension of the 

 vocal cords. Those characters of voice which we express 

 by such phrases as harsh, sweet, or sympathetic, depend 

 on the structure of the vocal cords of the individual; cords 

 which in vibrating emit only Harmonic partial tones 

 (p. 547) are pleasant; while those in which inharmonic 

 partials are conspicuous are disagreeable. 



The vocal cords alone would produce but feeble sounds; 

 those that they emit are strengthened by sympathetic re- 

 sonance of the air in the pharynx and mouth, the action of 



