[ 342 ] 



LXVII. Experimental Researches into the Physiology of the 

 Huma7i Voice. By John Bishop, Esq., Sfc. 8fc. 



[Continued from p. 277, and concluded.] 



THE falsetto, or voce di testa, has always been considered 

 a most embarrassing subject of research, and its peculiar 

 quality has excited the attention both of the physiologist and 

 of the musician. The change produced in the voice when pass- 

 ing from the falsetto into the common tone, or the reverse, is in 

 some persons very sensible to the ear, whilst in others it is al- 

 most imperceptible. It is remarkable that some individuals 

 have the faculty of producing, in the same pitch, three or four 

 tones, possessing either the falsetto or the common character, 

 a circumstance which indicates that the difference between 

 them depends rather upon an altered state of the vocal tube 

 than upon any change in the glottis. 



The falsetto has generally been ascribed to some particular 

 adaptation of the upper ligaments of the larynx. Dodart * 

 has attempted to prove that it is a supra-laryngeal function, 

 and that the nose becomes the principal tube of sound instead 

 of the cavity of the mouth. Bennati f also considers these 

 tones to be modified by the supra-laryngeal cavity, an opinion 

 not justified by the experiments which he has detailed. 



According to this hypothesis, we must suppose the influence 

 of the trachea to be entirely annulled ; but on what acoustic 

 principle this is to be effected he does not explain, nor indeed 

 can any one else. The changes observed by him in the pha- 

 rynx were undoubtedly associated with corresponding changes 

 in the whole length of the tube, and all the phaenomena he 

 has described may thus be readily explained. 



It was suggested to me by Mr. Wheatstone, that it was only 

 necessary to suppose the vocal tube capable of subdividing its 

 vibrating length to account for this peculiar character of tone. 

 Analogous effects are observed in the clarionet, the flute, 

 and other instruments ; the change taking place at the twelfth 

 of the fundamental note in the former instrument, and at the 

 octave in the latter. Having had an opportunity of examining 

 the phaenomena in some individuals possessing remarkably fine 

 voices, I placed my finger lightly on the larynx, and requested 

 them to gradually elevate the voice from the primary to the 

 falsetto tones, when, although the ear could scarcely distinguish 



• Mem. de I' Acad., 1707- 



f Becker ches sur le Mcchan. de la Voix Hum. 



