934 OP THE VOICE AND SPEECH. 



only half their length, the rima glottidis being partly closed ; and this explana- 

 tion is consistent with the fact that a far smaller quantity of air is required for 

 sustaining a falsetto note, than for a note of the ordinary register, even though 

 they should be of the same pitch. By Miiller, again, ifr is asserted that 

 in the production of the falsetto notes merely the thin border of the glottis 

 vibrates, so that the fissure remains distinctly visible ; whilst in the production 

 of the ordinary vocal tones, the whole breadth of the vocal ligaments is thrown 

 into strong vibrations which traverse a wider space, so that a confused motion is 

 seen in the lips of the glottis, rendering its fissure indefinite. It is not impos- 

 sible that both these doctrines are correct ; and that, in the production of fal- 

 setto notes the vocal ligaments are in contact with each other for part of their 

 length, and that only their thin edges are in vibration in the remainder. It 

 has been pointed out by Mr. Bishop (loc. cit.) that at the moment of transition 

 from the u chest voice" to the " falsetto voice," the crico-thyroid chink, which 

 was closed during the production of the highest note of the former, suddenly 

 opens on the production of the lowest note of the latter ; thus indicating that 

 the Vocal Cords are relaxed in the passage from the one to the other, as must 

 be the case, if, for the production of the same note, they be only put in vibra- 

 tion along a part of their length j so that it would not seem improbable that 

 the cause of those differences in the mode of transition which have been already 

 noticed, lies in the difference in the proportional amount of the vocal cords 

 which is thus thrown out of use by the partial approximation of the two lips of 

 the rima glottidis. It is further remarked by Mr: Bishop, that, in the passage 

 from the chest to the falsetto voice, the larynx descends from its previously 

 elevated position, and gradually rises again with the ascending scale of falsetto 

 notes ; and he mentions a case of double falsetto, in which a third register ex- 

 isted, and in which the relaxation of the Vocal cords and the descent of the 

 larynx were observed at its commencement, as at the commencement of the 

 second or ordinary' falsetto register. An entirely different theory of the falsetto 

 has been given, however, by MM. Petrequin and Diday j 1 who consider that the fal- 

 setto notes are not produced by the vibration of the vocal cords, but are really 

 " flute notes/' formed by the vibrations of the column of air to which the rima 

 glottidis then serves as the embouchure. This view harmonizes well with some 

 of the phenomena of the falsetto voice ; but it is open to the objections already 

 stated in regard to the flute theory generally. It may be added that some have 

 attempted to show that the falsetto depends upon a peculiar action of the parts 

 above the larynx ; but for this doctrine there is no foundation whatever. 



936. The various muscular actions, which are employed in the production and 

 regulation of the voice, are called forth by an impulse which has been shown 

 ( 751) to be really automatic in its operation, and to be completely under the 

 influence of guiding sensations, although usually originating in a Volitional 

 determination, or giving expression to Emotions or simply to Ideas. This, 

 however, has been proved to be true of all Volitional movements ; so that the 

 production of vocal tones constitutes no real exception. It may be safely 

 affirmed, that the simple utterance of sounds is in itself an Instinctive action ; 

 although the combination of these, whether into music or articulate language, 

 is a matter of acquirement, which is much more readily made by some indi- 

 viduals than by others. No definite tone can be produced by a Voluntary 

 effort, unless that tone be present to the Consciousness during an interval 

 however momentary either as immediately produced 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, 



1 " Gazette Medicale," 1844. 



