282 



Life and Health 



Voice is common to most animals, but speech is the 

 peculiar privilege of man. 



The organ of speech is perhaps the most delicate and 

 perfect motor apparatus in the whole body. It has been 

 calculated that upwards of nine hundred 

 movements per minute can be made by 

 the movable organs of speech during 

 reading, speaking, and singing. It is 

 said that a hundred different muscles of 

 the body are called into action in talking. 

 Each part of this delicate apparatus is 

 FIG. 153. Diagram- so admirably adjusted to every other that 

 matic Horizontal all parts of it act in perfect harmony. 



Section of Larynx. y 439 p roduction of Articulate Sounds. 



(Shows the direction of ,_ . , 



pull of the posterior To secure an easy and proper production 

 crico-arytenoid mus- o f articulate sounds, the mouth, teeth, 



cles, which abduct the , . , , A , , , , 



vocal cords. Dotted h P s > tongue, and palate should be in per- 

 lines show position in feet order. The modifications in articu- 

 lation which are occasioned by a defect 

 in the palate or in the uvula, and by the loss of teeth, are 

 sufficiently familiar. 



Many animals have the power of making articulated 

 sounds ; a few have risen, like man, to the dignity of 

 sentences, but accomplish this only by imitation of the 

 human voice. Both vowels and consonants can be dis- 

 tinguished in the notes of birds. 



Persons idiotic from birth are often incapable of produ- 

 cing any other vocal sounds than inarticulate cries, although 

 supplied with all the internal means of articulation. Per- 

 sons born totally deaf are in the same situation, though 

 from a different cause ; the one being incapable of imitating, 

 and the other being deprived of the power of hearing the 

 sounds to be imitated. 



