464 OF THE VOICE AND SPEECH. 



moistened and relaxed in various degrees. This observation may probably 

 be applied also to the trachea. 



611. These and numerous other muscular actions, which are employed in 

 the production and regulation of the voice, are effected by an impulse which 

 can scarcely be termed Voluntary, and the nature of which is a curious sub- 

 ject for inquiry. It may be safely affirmed, that the production of sounds is 

 in itself an Instinctive action; although the combination of these, whether into 

 music or articulate language, is a matter of acquirement. Now it might be 

 supposed that the AVill has sufficient power over the vocal muscles, to put 

 them into any state requisite for its purposes, without any further condition : 

 but a little self-experiment will prove that this is not the case. No definite 

 tone can be produced by a Voluntary effort, unless that tone be present to the 

 mind, during however momentary an interval, either as immediately conveyed 

 to it by an act of Sensation, recalled by an act of Conception, or anticipated 

 by an effort of the imagination. When thus present, the Will can enable the 

 muscles to assume the condition requisite to produce it; but under no other 

 circumstances does this happen, except by a particular mode of discipline 

 presently to be adverted to. The action itself, therefore, must be reduced to 

 the class of consensual movements ; and we must suppose that the will is 

 exercised in preparing the conditions requisite for it, rather than in directly 

 exciting it. That those who are unfortunately labouring under congenital 

 deafness, are thence debarred from learning the use of Voice in the ordinary 

 manner, is well known ; the consensual action cannot be excited, either 

 through sensations of the present, or conceptions of the past ; and the imagi- 

 nation is entirely destitute of power to suggest that which has been in no 

 shape experienced. But such persons may be taught to speak in an imperfect 

 manner, by causing them to imitate particular muscular movements, which 

 they may be made to see; and it is evident, that they must be guided in the 

 imitation and ordinary performance of those movements, by the common 

 muscular sensations which accompany them, and not by the sensations con- 

 veyed through the Auditory nerve, which are ordinarily by far the most pre- 

 cise guides. Many instances, indeed, are on record, in which persons entirely 

 deaf were enabled to carry on a conversation in the regular way; judging of 

 what was said, by the movements of the lips and tongue, which they had 

 learned to connect with particular syllables ; and regulating their own voices 

 in reply, by their voluntary power, guided by muscular sensation.* 



[In the foregoing account of the Physiology of Voice, the author has been chiefly guided 

 by the excellent paper by Mr. Willis 'in the Transactions of the Cambridge Philosophical 

 Society, vol. iv. ; and by the elaborate investigations of Miiller and his coadjutors, as detailed 

 in the Fourth Book of his Physiology.] 



2. Of Articulate Sounds. 



612. The larynx, as now described, is capable of producing those tones of 

 which Voice fundamentally consists, and the sequence of which becomes 

 Music : but Speech consists in the modification of the laryngeal tones, by 

 other organs, intervening between the Glottis and the Os Externum ; so as 

 to produce those articulate sounds, of which Language is formed. It cannot 

 be questioned that Music has its language ; and that it is susceptible of ex- 

 pressing the emotional states of the mind, among those at least who have 

 been accustomed to associate these with its varied modes, to even a higher 

 degree than articulate speech. But it is incapable of addressing the intellect, 

 by conveying definite ideas of objects, properties, actions, &c., in any other 



* See Jolmstone on Sensation, p. 128. 



