THE PRODUCTION OF THE VOICE. 545 



a voice depends, of course, in the main, on the extent to which the 

 degree of tension of the vocal cords can be thus altered. In the produc- 

 tion of a high note the vocal cords are brought well within sight, so as 

 to be plainly visible with the help of the laryngoscope. In the utter- 

 ance of grave tones, on the other hand, the epiglottis is depressed and 

 brought over them, and the arytenoid cartilages look as if they were 

 trying to hide themselves under it (fig. 348). The epiglottis, by being 



Fig. 348. View of the upper part of the larynx as seen by means of the laryngoscope during 

 the utterance of a grave note, c, Epiglottis ; s, tubercles of the cartilages of Santorini ; a, aryt- 

 enoid cartilages; z, base of the tongue; ph,ihe posterior wall of the pharynx. (Czermak.) 



somewhat pressed down so as to cover the superior cavity of the larynx, 

 serves to render the notes deeper in tone and at the same time somewhat 

 duller, just as covering the end of a short tube placed in front of 

 caoutchouc tongues lowers the tone. In no other respect does the 

 epiglottis appear to have any effect in modifying the vocal sounds. 



The degree of approximation of the vocal cords also usually corre- 

 sponds with the height of the note produced ; but probably not always, 

 for the width of the aperture has no essential influence on the height of 

 the note, as long as the vocal cords have the same tension : only with a 

 wide aperture the tone is more difficult to produce and is less perfect, 

 the rushing of the air through the aperture being heard at the same 

 time. 



No true vocal sound is produced at the posterior part of the aperture 

 of the glottis, that, viz., which is formed by the space between the 

 arytenoid cartilages. For if the arytenoid cartilages be approximated 

 in such a manner that their anterior processes touch each other, but yet 

 leave an opening behind them as well as in front, no second vocal tone 

 is produced by the passage of the air through the posterior opening, but 

 merely a rustling or bubbling sound ; and the height or pitch of the 

 note produced is the same whether the posterior part of the glottis be 

 open or not. 



THE VOICE IK SINGING AND SPEAKING. 



Varieties of Vocal Sounds. The laryngeal notes may observe three 

 different kinds of sequence. The first is the monotonous, in which the 

 notes have nearly all the same pitch as in ordinary speaking; the 

 variety of the sounds of speech being due to articulation in the. mouth. 



35 



