658 SPEECH. [BOOK in 



the mouth more closed than in a, but the lips, instead of being re- 

 tracted as in i and e, are somewhat protruded, so that the sounding 

 tube is prolonged. The greatest length of the tube is reached in u, 

 (oo), in which the larynx is depressed and the lips protruded as 

 much as possible. While the two latter vowels are being uttered, 

 the general form of the buccal cavity is that of a flask with a 

 short neck and a small opening, the orifice being smaller for u than 

 for o. 



Each of these various 'vowel' forms of the mouth possesses a 

 note of its own, one towards which it acts as a resonance chamber. 

 Thus if several tuning-forks of various pitch be held while sounding 

 before a mouth which has assumed the particular form necessary 

 for sounding U, it will be found that the resonance will be particu- 

 larly great with the fork having the pitch of the bass 6-flat. Simi- 

 larly other and higher notes will be intensified when the mouth is 

 moulded to utter the other vowels. And it is the experience of 

 singers that each vowel is sung with peculiar ease on a note having 

 a prominent overtone corresponding to the tone proper to the 

 mouth when moulded to utter the vowel. The precise nature of 

 the vowel sounds is however still disputed. 



As the vibrations are travelling through the pharyngeal and 

 buccal cavities, the posterior nares are closed by the soft palate; 

 and it may be shewn, by holding a flame before the nostril, that no 

 current of air issues from the nose when a vowel is properly said or 

 sung. When the posterior nares are not effectually closed the 

 sound acquires a nasal character. The same happens when the 

 anterior nares are closed, as when the nose is held between the 

 fingers, the nasal chamber then forming a cavity of resonance. 



Consonants. 



^ Vowels are, as their name implies, the only real vocal sounds ; 

 it is only on a vowel that a note can be said or sung. Our speech 

 however is made up not only of vowels but also of consonants, i.e. 

 of sounds which are produced not by the vibrations of the vocal 

 cords but by the expiratory blast being in various ways interrupted 

 or otherwise modified in its course through the throat and mouth. 



The distinction between the two is however not an absolute one, 

 since, as we have seen, the characters of the several vowels depend 

 on the form of the mouth, and in the production of some conso- 

 nants (B, D, M, N, &c.) vibrations of the vocal cords form a neces- 

 sary though adjuvant factor. 



Consonants have been classified according to the place at which 



