352 APPLIED PHYSIOLOGY 



air is simply breathed through the mouth, while the tongue 

 and lips cut it off at intervals as though a sound were 

 being made. 



634. A simple sound continuously uttered is a vowel 

 sound. If the mouth is simply opened without effort, the 

 sound 'formed will be that of a as in father. When the 

 mouth is closed the most, it forms the sound oo as in room.' 

 A consonant sound is a vowel sound suddenly modified in 

 either its beginning or ending. For instance, when the 

 tip of the tongue is held against the palate just back of the 

 teeth, and a vowel sound is begun by forcibly blowing it 

 away, the sound will be either t, d } or th. 



635. Rate of talking. A public speaker will ordinarily utter 

 125 words a minute. On an average each word will be composed of, 

 at least, four different sounds. Thus the vocal organs must make 600 

 separate adjustments each minute, or 10 each second. 



636. Relation of sound and speech. Words spoken must 

 first be heard. So no matter what the race of a child, it will speak 

 exactly the speech which it hears. If a child is brought up in com- 

 pany with an ignorant nurse girl, its speech will be her brogue. On 

 the other hand, if the child is brought up among educated and refined 

 persons, it will speak an elegant tongue. 



A deaf person has great difficulty in learning to speak at all, for he 

 can have no idea of the sound which he should make. Without special 

 instruction deaf persons would never learn to speak at all, but by letting 

 them see or feel the position of the lips and tongue in forming words, 

 they learn to place their own parts in the same position and so finally 

 learn to talk. 



637. Necessity of the tongue in speech. The tongue is 

 usually considered to be so necessary in speech that the language itself 

 is called a tongue. As man's mouth is constructed the tongue does do 

 the most important part of forming words, but if the organ is removed 

 as far back as possible, th.e stump can still form intelligible words. 

 Sometimes the front part of the tongue is bound down or " tied " so 

 that it cannot move so freely as it should. This is supposed to hinder 

 a child in talking, but in reality it does not. 



