THE RESPIRATION 



tinguished (1) Yowel Sounds. These are musical sounds 

 produced by a blast of air which is so modified by changing 

 the shape of the mouth as to produce the well-known a, e, i, 

 o, u (Fig. 143). 



In sounding a, the mouth resembles a funnel with the 

 wide part forward. 



In i, it may be compared to a flask with the belly behind 

 and the neck forward. 



In u, the flask is reversed, the belly being forward. 



In o, the mouth is intermediate between its position in 

 u and a, and in e between a and i. 



(2) Consonant Sounds. These are more of the nature of 

 noises irregular vibration. They are produced either (1) 

 at the lips, (2) between the teeth and hard palate and 

 the tongue, or (3) at the soft palate and back of the tongue. 

 At these situations sounds may be produced (1) by closing 

 the orifice and then suddenly forcing it open, (2) by sending 

 a current of air over a narrowing produced at one of these 

 places, (3) by setting the edges of the narrowing in vibration. 

 When the mouth is closed at one of these situations and air 

 is forced through the nose the nasal consonant sounds result. 



Thus, according to their mode of production, the consonant 

 sounds may be classified into explosives, aspirates, vibratories, 

 or nasals. 



