i2 3 6 ON VOCAL SOUNDS. 



of the heart is closed during systole, the valves being distended from 

 below. According to Wyllie, therefore, the principal function of the 

 false cords is to close the glottis tightly against an expiratory blast of 

 air, and thus enable the animal to fix the ribs for effort. This view is 

 borne out by the researches of Brunton and Cash, 1 who not only con- 

 firmed Wyllie's statements by new experiments, but carried the investi- 

 gation into the realms of comparative physiology. They point out that 

 in those animals whose habits required fixation of the thorax, for striking 

 or climbing, the ventricular bands (false cords) are well developed ; 

 and, conversely, animals which do not require strong fixation of the 

 thorax, have ventricular bands of insignificant proportions. They 

 further observed, that in animals in which vomiting is easily performed, 

 the ventricular bands are well developed, and thus enable the animal to 

 fix the thorax for the effort in a much more effectual way than in those 

 animals in which the ventricular bands are small or absent. 



The oral, pharyngeal, and nasal cavities have considerable influence 

 upon the voice. This has already been discussed. In general, however, 

 it may be said that these cavities, the pharyngeal and nasal in particular, 

 confer a clear ringing character upon the voice ; when they are affected 

 by catarrh the voice has a muffled quality. 



Whispering. 



Arnott, 2 in 1826, defined whispering as articulation without voice, 

 and for a long time it was supposed that during this act the cords were 

 wide apart, allowing the breath to pass freely. Briicke was the first to 

 dispute this statement, maintaining that the vowels are always produced 

 in the larynx even in whispering. This view, at first sight, appears to 

 be supported by an observation made by Czermak. He examined the 

 larynx with the mirror during whispering, and found that an open 

 triangular space is present at the posterior portions of the glottis, while 

 the anterior portions of the vocal cords take up positions very similar 

 to those which they assume during ordinary vocalisation. The air 

 rushing through this triangular area, according to him, produces the 

 fricative noise characteristic of whispering. 3 



The matter is not, however, by any means settled by this observation, 

 since the open condition of the mouth necessary for laryngoscopic 

 investigation would prevent true whispering, which is invariably per- 

 formed with an almost closed buccal cavity. Moreover, it has been 

 noticed that, after excision of the larynx, whispering is still possible. 4 

 Although it may be questioned whether this is altogether the same as 

 ordinary whispering, nevertheless, to judge by one's own sensations in 

 performing the act, the part played by the vocal cords appears to be 

 insignificant, if not altogether negligible. 



1 Joum. Anat. and Physiol., London, vol. xvii. p. 363. 



2 "Physics," 5th edition, p. 640. 



3 Czermak, Sitzungsh. d. k. Akad. d. Wisscnsch., Math. Nat. CL, Wien, 1866, Bd. Hi. 



4 Macdonald and Symonds, Brit. Med. Journ., London, 1889, vol. i. p. 996. 



