CHAPTER XXXIII 

 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 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 produced 

 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 commonly known as the "breaking of the 

 .voice." Every voice, while 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 (Chap. XIV) are pleasant; while those in which in- 

 harmonic partials are conspicuous are disagreeable. 



The vocal cords alone would produce but feeble sounds; those 

 that they emit are strengthened by sympathetic resonance of the 

 air in the pharynx and mouth, the action of which may be com- 

 pared to that of the sounding-board of a violin. By movements 

 of throat, soft palate, tongue, cheeks, and lips the sounds emitted 

 from the larynx are altered or supplemented in various ways, and 

 converted into articulate language or speech. 



The Larynx lies in front of the neck, beneath the hyoid bone 

 and above the windpipe; in many persons it is prominent, caus- 



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