490 MUSCLE-NERVE PHYSIOLOGY 



size and shape of the larynx and mouth cavity which influence the voice 

 quality can be controlled to some extent during singing, and this is a special 

 point of training in voice culture. 



Speech. Besides the musical tones formed in the larynx a great 

 number of other sounds can be produced in the vocal tubes, between the 

 glottis and the external apertures of the air-passages, the combination of which 

 sounds into different groups to designate objects, properties, actions, etc., 

 constitutes language. The languages do not employ all the sounds which can 

 be produced in this manner, the combination between certain sounds being 

 often difficult. Those sounds which are easy of combination enter, for the 

 most part, into the formation of the greater number of languages. Each 

 language contains a certain number of such sounds, but in no one are all 

 brought together. On the contrary, different languages are characterized by 

 the prevalence in them of certain classes of these sounds, while other sounds 

 are less frequent or altogether absent. 



Articulate Sounds. The sounds produced in speech, or the articu- 

 late sounds, are commonly divided into vowels and consonants: the distinc- 

 tion between which is that the sounds for the former are generated by the 

 larynx, while those for the latter are produced by interruption of the current 

 of air in some part of the air-passages above the larynx. The term consonant 

 has been given to these because several of them are not properly sounded, ex- 

 cept consonantly with a vowel. Thus, if it be attempted to pronounce aloud 

 the consonants b, d, and g, or their modifications, p, t, k, the intonation fol- 

 lows them only in their combination with a vowel. To recognize the essential 

 properties of the articulate sounds, it is necessary first to examine them as they 

 are produced in whispering, and then investigate which of them can also be 

 uttered in a modified character conjoined with vocal tone. By this procedure 

 we find two series of sounds: in one the sounds are mute, and cannot be 

 uttered with a vocal tone; the sounds of the other series can be formed inde- 

 pendently of voice, but are also capable of being uttered in conjunction with it. 



All the vowels can be expressed in a whisper without vocal tone, that is, 

 mutely. These mute vowel sounds differ, however, in some measure, as to 

 their mode of production, from the consonants. All the mute consonants are 

 formed in the vocal tube above the glottis, or in the cavity of the mouth or 

 nose, by the mere rushing of the air between the surfaces differently modified 

 in disposition. But the sound of the vowels, even when mute, has its source 

 in the glottis, though its vocal cords are not thrown into the vibrations necessary 

 for the production of voice; and the sound seems to be produced by the passage 

 of the current of air between the relaxed vocal cords. The same vowel-sound 

 can be produced in the larynx when the mouth is closed, the nostrils being 

 open, and the utterance of all vocal tone avoided. The sound, when the mouth 

 is open, is so modified by varied forms of the oral cavity as to assume the 

 characters of the vowels a, e, i, o, u, in all their modifications 



