356 NATURE OF VOCAL SOUNDS. 



individual is capable of singing in two different voices, known as chest 

 notes and falsetto notes. The chest notes are produced by the ordinary 

 mode of vibration ; the falsetto notes, which are purer or more fluty, are 

 considered to be probably due to vibrations of the harmonic subdivisions 

 of the column of air in the trachea, or to vibrations of the inner borders 

 of the vocal cords. 



While thus song is laryngeal, speech, which is a modification thereof, 

 Speaking ani- * s ora *' or P ro duced ^7 tne mouth. Man is not alone endow- 

 mais and ma- ed with the faculty of uttering articulate sounds : there are 

 several other animals which, by education, may be taught to 

 express them. Ingenious mechanics have also repeatedly invented in- 

 struments, the construction of which, being upon the same principle as 

 that of the vocal organs, has combined the sounds of letters into words, 

 and even into sentences, a convincing proof not only of the mechanical 

 nature of articulate sounds, but also of the perfect manner in which the 

 natural mechanism is understood. Animals which have been taught to 

 speak may also be regarded as automata, for they have no comprehen- 

 sion of what it is they are uttering, and never produce articulate com- 

 binations spontaneously, but only as the result of instruction. 



Like the automata just alluded to, the human voice expresses words 

 Words originate ^ v com bining their constituent letters together. Gramma- 

 by combining rians divide letters into two groups, vowels and consonants, 

 defining the vowel as a sound that can be uttered by itself, 

 the consonant taking its name' from the fact that it can only be uttered 

 consonantly with a vowel. By personal experiment, it may be easily 

 proved that the vowel is a continuous sound, which may be kept up just 

 as long as the breath will enable, and, on examining the position of the 

 Consonants tongue and other movable portions of the mouth, the particular 

 and vowels, arrangement necessary for pronouncing the letters #, 0, z, o, u, 

 or the sixteen or eighteen vowel sounds of the Continental languages, will 

 be detected. It will be found that the determining condition is, for the 

 most part, the peculiar modification of the oral apertures. It will also 

 be discovered that articulation is wholly independent of the larynx, since 

 merely by expelling the air through the mouth, without permitting any 

 laryngeal sound to be formed, all the letters may be articulated in a whis- 

 per. M. Deleau has illustrated this fact in an ingenious way by put- 

 ting an India-rubber tube through the nostril, so as to reach the poste- 

 rior portion of the mouth, and causing another individual to blow gently 

 through it ; while the organs of the mouth are silently thrown into those 

 Nature of whis- positions necessary for the utterance of any particular sound, 

 penng. t ^at ar ti c ulate sound will at once appear in whispers ; but 



if, while this is being done, the larynx is permitted to yield a sound, two 

 voices then are heard, one in audible speech and one in a whisper, the 



