Ill 



PHONATION AND ABTICULATION 



151 



open, but only in the middle part, where it forms a comparatively 

 wide space through which the expired air can readily escape 

 (Garcia) ; this produces greater resonance in the pharyngo-buccal 

 cavity, and vibrations of the cranial bones (hence " head " voice) ; 

 the false vocal cords are tensely stretched, and approach the true 

 cords, or, according to some authors, actually come into contact 

 with them ; the vibrations of the cords are only visible in the 

 most forward part of their free edges (Fig. 99a). Other observers, 

 on the contrary, state that in the head register the glottis is open 

 in its entire length, although it is reduced to a linear slit (French). 

 Possibly all singers do not employ the same laryngeal mechanism 

 in the different registers. 



Among the contradictory interpretations of the fundamental 

 differences between the chest .register and the head register, that 

 of Lehfeldt (1835) found wide acceptance, and was adopted by 



Fio. 99a. Aperture of glottis during emission of high notes (C), with chest register ; and of 

 highest notes (D), with head register. (Mandl.) 



Job. Miiller and many other physiologists. He assumed that in 

 the falsetto voice only the free edges of the vocal cords are thrown 

 into vibration, while in the chest voice the whole of the cords 

 vibrate. Bonders held that in the chest register the musculus 

 vocalis (internal thyro-arytenoid), being contracted and tense, 

 participates in the vibrations of the cords, and that its weight 

 drags down the pitch. In the falsetto register, on the other hand, 

 as the musculus vocalis is relaxed, the vibratory movement is con- 

 fined to the edges of the cords ; the pitch consequently becomes 

 higher owing to the reduction of the vibrating mass. The relaxa- 

 tion of the musculus vocalis accounts for the comparative breadth 

 of the glottis and the more rapid absorption of the reserve air, as 

 well as the more marked fatigue and greater vibration of the head. 

 After Oertel's laryngoscopical observations (1882) by Mach's 

 stroboscope method (intermittent illumination of the glottis) this 

 theory lost ground, and was gradually replaced by another, 

 according to which, when the falsetto voice is produced, nodal lines 

 are formed in the vocal cords parallel to their free borders. The 

 increased height of the falsetto notes is therefore due, not to 



