936 OF THE VQICE AND SPEECH. 



unless conjoined with a vowel. The distinction may be more correctly laid 

 down, however, in this manner: the Vowel sounds are continuous tones, modi- 

 fied by the form of the aperture through which they pass out j whilst in sound- 

 ing Consonants, the breath suffers a more or less complete interruption, in its 

 passage through parts anterior to the larynx. Hence the really simple Vowel 

 sounds are capable of prolongation during any time that the breath can sustain 

 them ; this is not the case, however, with the real Diphthongal sounds (of 

 which it will presently appear that the English i is one) ; whilst it is true of 

 some Consonants. It seems to have been forgotten by many of those who have 

 written upon this subject, that the laryngeal voice is not essential to the forma- 

 tion of either vowels or consonants ; for all may be sounded in a whisper. It is 

 very evident, therefore, that the larynx is not primarily concerned in their pro- 

 duction ; and this has been fully established by the following experiment : A 

 flexible tube was introduced by M. Deleau through his nostril into the pharynx, 

 and air was impelled by it into the fauces ; then, closing the larynx, he threw 

 the fauces into the different positions requisite for producing articulate sounds, 

 when the air impelled through the tube became an audible whisper. The ex- 

 periment was repeated, with this variation that laryngeal sounds were allowed 

 to pass into the fauces ; and each articulated letter was then heard double, in a 

 proper voice and in a whisper. 



939. That the Vowels are produced by simple modifications in the form of 

 the external passages, is easily proved, both by observation and by imitative 

 experiment. When the mouth is opened wide, the tongue depressed, and the 

 velum palati elevated, so as to give the freest possible exit to the voice, the 

 vowel a in its broadest form (as in ah) is sounded. 1 On the other hand, if the 

 oral aperture be contracted, the tongue being still depressed, the sound oo (the 

 Continental u) is produced. If attention be paid to the state of the buccal cavity 

 during the pronunciation of the different vowel sounds, it will be found to un- 

 dergo a great variety of modifications, arising from varieties of position of the 

 tongue, the cheeks, the lips, and velum palati. The position of the tongue is, 

 indeed, one of the primary conditions of the variation of the sound ; for it may 

 be easily ascertained that, by peculiar inflexions of this organ, a great diversity 

 of vowel sounds may be produced, the other parts remaining the same. Still 

 there is a certain position of all the parts, which is most favorable to the forma- 

 tion of each of these sounds; but this could not be expressed without a length- 

 ened description. The following table, slightly altered from that of Kempelen, 

 expresses the relative dimensions of the buccal cavity and of the oral orifice, for 

 some of the principal of these ; the number 5 expressing the largest size, and the 

 others in like proportion : 



Vowel. Sound. Size of oral opening. Size of buccal cavity. 



a as in ah 5 5 



a as in name 4 2 



e as in theme 3 1 



o as in cold 2 4 



oo as in cool 1 5 



These are the sounds of the five vowels, a, e, i, o, u, in most Continental 

 languages ; and it cannot but be admitted that the arrangement is a much more 

 natural one than that of our own vowel series. The English a has three distinct 

 sounds capable of prolongation * the true broad a of ah, slightly modified in 



1 This sound of the vowel a is scarcely used in our language, though very common in 

 most of the continental tongues ; the nearest approach to it in English is the a in far ; but 

 this is a very perceptible modification, tending towards au. 



2 The short vowel sounds, as a in fat, e in met, o in pot, &c., are not capable of pro- 

 longation. 



