442 VOICE. [CHAP. xxxi. 



glottis. By increasing the weight which stretches the vocal 

 chords, the height of the notes is raised ; on the other hand, the 

 relaxation of the chords lowers the notes : a register of about three 

 octaves may be formed in this way. Even after all the parts 

 which lie over the vocal chords have been removed, these variations 

 of sound may still be produced. 



The action of the vocal organ in man appears to approach 

 more nearly to that of a reed instrument than to a stringed instru- 

 ment. The former is characterized by being provided with a 

 flexible vibrating tongue, against which the air can be propelled 

 so as to throw the tongue into vibration, and to excite a musical 

 sound. Such is the mechanism in the organ-pipe, hautboy, 

 bassoon, accordion, and other instruments ; the form and disposi- 

 tion of the tongue, and the material of which it is made, differing 

 in each instrument. 



Chest Voice. In the larynx, as before remarked, the note may 

 be changed, by varying the tension of the vocal chords, pro- 

 vided they be parallel and sufficiently close to each other. When 

 a high note is to be produced, the head is raised and the larynx 

 elevated, in order that the vocal chords may be rendered tense ; on 

 the other hand, if we wish to sound a very low note, the chin 

 must be depressed upon the chest, so as to facilitate the relaxa- 

 tion of the vocal ligaments. At the same time, the strength of 

 the blast of air exerts a considerable influence upon the pitch of 

 the note. In reed instruments, it has been found that the note 

 can be rendered higher by increasing the force of the blast. 



Falsetto Notes. The sounds to which we have been referring 

 are produced solely by the vibration of the chordse vocales ; modi- 

 fied no doubt by the epiglottis, soft palate, etc., and the laryngeal 

 cavity below. These notes are all termed chest notes; but in 

 man tones can be generated very different from those which 

 can be imitated by experiments upon the dead larynx. These 

 are the falsetto notes. The precise mode of their production is 

 obscure. From the experiments of Miiller end Lehfeldt, it is 

 probable that these falsetto notes are produced by the vibration 

 of the inner portion of the borders of the vocal ligaments solely. 

 Majendie and Mayo accounted for them upon the view, that only 

 half the length of the chords was thrown into vibration. 



Mr. Bishop has shown, that in the transition from the chest 

 note to the falsetto note the crico -thyroid chink opens, having been 

 closed immediately before, during the production of the highest 

 note of the chestvoice, so that the vocal ligaments become relaxed; 



