M. Garcia on the Human Voice. 831 



cartilages, and by the ligaments, become gradually shorter as the 

 voice ascends ; at the notes la, si, ^EdEE«EE> the apophyses take 



part only at their summits ; and in these notes there results a weak- 

 ness similar to that which we have remarked in the chest-notes an 

 octave below. At the notes dofl;, re, ZE^irE^rE:, the ligaments 



4 4 y : 



alone continue to act ; then begins the series of notes called head- 

 voice. The moment in which the action of the apophyses ceases, 

 exhibits in the female voice a very sensible difference at once to the 

 ear and in the organ itself. Lastly, we verify, that, up to the highest 

 sounds of the register, the glottis continues to diminish in length 

 and in width. 



If we compare the two registers in these movements, we shall find 

 some analogies in them : the sides of the glottis, formed at first by 

 the apophyses and the ligaments, become shorter by degrees, and 

 end by consisting only of the ligaments. The chest-register is 

 divided into two parts, corresponding to these two states of the 

 glottis. The register of falsetto- head presents a complete similarity, 

 and in a still more striking manner. 



On other points, on the contrary, these same registers are very 

 unlike. The length of the glottis necessary to form a falsetto note, 

 always exceeds that which produces the unison of the chest. The 

 movements which agitate the sides of the glottis are also aug- 

 mented, and keep the vibrating orifice continually half opened, which 

 naturally produces a great waste of air. A last ti'ait of difference, 

 is in the increased extent of that elliptic surface. 



All these circumstances, which we shall refer to again, show in 

 the mechanism of the falsetto, a state of relaxation, which we do not 

 find in the same degree in the chest-register. 



Manner in tuhich the sounds are formed. 



As we have just said, and what we have seen proves it, the in- 

 ferior ligaments, at the bottom of the larynx, form exclusively the 

 voice, whatever may be its register or its intensity ; for they alone 

 vibrate at the bottom of the larynx*. But by virtue of what prin- 

 ciple is the voice formed ? It seems to me, that the answer to this 

 question can be but this ; the voice is formed in one unique manner, — 

 by the compressions and expansions of the air, or the successive and 

 regular explosions which it produces in passing through the glottis. 



The ligaments of the glottis are situate about the mean level of 

 the upper border of the cricoid, close the passage, and present a 

 resistance to the air. As soon as the air has accumulated suffi- 

 ciently, it ])arts these folds and produces an explosion. But at the 

 same instant, by virtue of their elasticity, and the pressure from be- 

 low being relieved, they meet again to give rise to a fresh explosion. 

 A series of these compressions and expansions, or of explosions, 

 occasioned by the expansive force of the air and the reaction of the 

 glottis, produces the voice. 



* We gladly acknowledge that this most important fact has been already 

 announced hy J. .Miillcr, although wa have our ohjections to tlic theory which 

 accotnpauies it. — Ilandbucfi der Physiologie des Metucfien. 



