562 VOICE AND SPEECH. 



yellow and blue we produce white. Thus also may elementary sounds be blended so as 

 to produce all possible varieties of clang-tint. After having resolved the human voice 

 into its constituent tones, Helmholtz was able to imitate these tones by tuning-forks, and, 

 by combining them appropriately together, to produce the clang-tints of all the vowels." 



Consonants. Some of the consonants have no sound in themselves and serve merely to 

 modify vowel-sounds. These are called mutes. They are &, <?, &, p, t, and c and g hard. 

 Their office in the formation of syllables is sufficiently apparent. 



The consonants known as semivowels are, /, I, m, n, r, *, and c and g soft. These 

 have an imperfect sound of themselves, approaching in character the true vowel-sounds. 

 Some of these, I, m, n, and r, from the facility with which they flow into other sounds, 

 are called liquids. Orthoepists have farther divided the consonants with reference to the 

 mechanism of their pronunciation : d, j, s, t, z, and g soft, being pronounced with the 

 tongue against the teeth, are called dentals ; d, g, j, k, I, 72, and q are called palatals ; 6, 

 j9,/, u, and m are called labials ; m, n, and ng are called nasals; and &, g, and c and g 

 hard are called gutturals. After the description we have given of the voice, it is not 

 necessary to discuss farther the mechanism of these simple acts of articulation. 



For the easy and proper production of articulate sounds, absolute integrity of the 

 mouth, teeth, lips, tongue, and palate is required. We are all acquainted with the modi- 

 fications in articulation, in persons in whom the nasal cavities resound unnaturally, from 

 imperfection of the palate ; and the slight peculiarities observed after loss of the teeth 

 and in hare-lip are sufficiently familiar. The tongue is generally regarded, also, as an 

 important organ of speech, and this, is the fact in tho great majority of cases ; but 

 instances are on record in which distinct articulation has been preserved after complete 

 destruction of this organ. These cases, however, are unusual, and they do not invalidate 

 the great importance of the tongue in ordinary speech. 



It is thus seen that speech consists essentially in a modification of the vocal sounds 

 by the accessory organs, or by parts situated above the larynx ; the latter being the true 

 vocal instrument. While the peculiarities of pronunciation in different persons and the 

 difficulty of acquiring foreign languages after the habits of speech have been formed show 

 that the organs of articulation must perform their function with great accuracy, their 

 movements are simple, and they vary with the peculiarities of different languages. The 

 most interesting question, in its general physiological relations, is that to which a great 

 part of this chapter has been devoted ; and that is the mechanism of the production of 

 the voice. 



