436 AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



sympathetic resonance of the thorax the reinforcement of laryngeal tones may 

 here be altered somewhat, as in the month itself. 1,2 



Whispering- is a mode of speech in which noise largely replaces pendular 

 musical vibrations. The glottis remains more or less widely open and the 

 vocal cords are not tense; the vibrations arc produced both in the larynx and 

 in the buccal-pharyngeal chambers. Vowel sounds may be produced in whis- 

 pering as well as in true voice because, from the multitude of irregular vibra- 

 tions, those waves are reinforced which make up the vowel sounds determined 

 by the set of the mouth. Gentle whispering requires much less effort than does 

 speaking, and inspiratory whispering is less easily distinguished from expiratory 

 than is the strained voice of inspiration from the natural sound of expiration. 

 Consonants, as already indicated, may sometimes play the part of vowels, but 

 pure consonants do not appear in syllables except in combinations with vowels, 

 which combinations always carry the syllable accent. 



Consonants. — The distinction between consonants and vowels lies in the 

 fact that the tones of the latter are produced by vibration of the vocal cords, 

 the parts above which act only as resonance-boxes and modify the sound, and 

 never offer marked obstruction to the exit of air; whereas in the formation of 

 consonants there is some adjustment in the mouth-passage either in the nature 

 of a local narrowing, by which a peculiar noise is added to the vocal sound, or 

 in the nature of a sudden closing or opening of the air-channel by which a 

 characteristic noise is likewise added to the vocal sound. In other words, the 

 parts above the larynx make the sounds of consonants but only modify those 

 of vowels. 3 No sharp line of separation can be drawn between vowels and 

 consonants, since certain characters, according to their associations, now fall 

 into one, now into another class. In the classification of consonantal sounds 

 much confusion exists, dependent chiefly on the fact that several letter charac- 

 ters change their modes of formation and expression with their place in the 

 syllable. The same facts, also, are expressed by different authors by different 

 nomenclatures, and sounds occur in one language that are not found in another. 

 Adopting the general classification of (Jriitzner, 4 we may divide consonants 

 into the following three groups: 



1. Semi-vowels or liquids, which can be used either as vowels or consonants; 

 this group includes the sounds m, n, ng, I, and /•. In expressing the function 

 of a consonant, the letter is not to be sounded as if it stood alone, but its cha- 

 racter given as actually expressed in a syllable; thus the sound of p is not pee, 

 Inn is the abbreviated labial expression, as in pack or jticrv when all the letters 

 are eliminated after the first. Of the liquids the v. m, and ng (sometimes 

 called "resonants") have the nature of vowels when final (as in him, hen, 

 being), and are then produced by vibration of the vocal cords, the lips having 

 previously been closed for the m, and the tongue applied to the roof of the 

 mouth to cut off the exit of air for n and ng ; the expelled air escapes alto- 

 gether through the nose, which acts as a resonance-chamber. Used as conso- 



1 Op. cit., p. 93. -.wall and Pollard: Journal of Physiology, 1890. vol. xi., p. 159. 



"Griitzner: op. cit., \>. 196. 4 Op. cit., p. 197. 



