278 



THE VOICE AND SPEECH 



Arytenoid cartilages 



Vocal cords 



Pitch. The pitch of the voice depends upon the 

 tension of the vocal cords. If they are made very tense 



by their adjusting muscles, the 

 voice is of high pitch. If, on 

 the contrary, they are but 

 slightly tense, the pitch is low. 

 The range of pitch differs in 

 different individuals. A large 

 larynx with long thick vocal 

 cords results in a deep bass 

 voice ; a smaller larynx with 

 shorter thinner vocal cords re- 

 sults in a tenor voice. In women 

 and children, the larynx is 

 distinctly smaller than in men 

 and their voices are of cor- 

 respondingly higher pitch. In 

 children, as the larynx increases 

 in size, their voices, especially 

 those of boys, become lower 

 pitched. 



Timbre. The quality, or timbre, of the voice in con- 

 trast to its pitch, depends upon the fact that the vocal 

 cords, like violin and piano strings, vibrate not only as 

 a whole but in halves, quarters and even in shorter 

 lengths. As a result, the vibration of the whole length, 

 or fundamental vibration, is supplemented by the higher, 

 or overtone, vibrations of the sections. These overtones 

 are octaves of the fundamental tone. If the vocal cords 

 are smooth and of the same weight and tension, the voice 

 is greatly enriched by the overtones and is musical. If, 

 however, the cords do not vibrate together because of 

 inequality of weight or tension, the vibrations of the two 

 cords do not coincide. In addition, their overtones, not 



Position in 



rapid 

 inspiration 



FIG. 150. Diagrams showing 

 various positions of the vocal 

 cords and their adjustment 

 by the muscles controlling 

 the arytenoid cartilages. 



