620 COMPARATIVE. HISTORICAL. 



the escape of air produces a kind of voice. Finally, some mussels (pecten) are 

 able to produce sounds by beating their shells on each other. In the animal 

 world the utterance of sounds serves principally as a decoy. 



Historical. The Hippocratic school was aware of the fact that division of 

 the trachea abolishes the voice. Aristotle made numerous contributions regarding 

 the voice and the venting of air in animals. The true insight into the cause of 

 voice-formation was, however, hidden from him, as well as from Galen. The 

 latter compared the vocal bands with the reeds of a shepherd's pipe. Loss of 

 voice in conditions of extreme weakness, especially after hemorrhage, was known 

 to the ancients. Galen observed loss of voice after establishment of double 

 pneumothorax, further after section of the intercostal muscles or their nerves, 

 also after destruction of the lower portion of the spinal cord, even when the dia- 

 phragm still performed its functions. He gave the laryngeal cartilages the names 

 that they still bear, recognized some of the laryngeal muscles, and asserted that 

 the voice sounds only when the glottis becomes narrowed. Dodart (1700) first 

 attributed the development of the voice to the vibration of the vocal bands as 

 a result of the air passing through the glottis ; as the tension of the bands becomes 

 greater the pitch of the voice increases. The Paris professor Ferrein first de- 

 clared correctly in 1741 that the width of the glottis is without influence on the 

 pitch of the voice; he was the first to produce sounds in the excised larynx by 

 blowing air through it. 



The study of phonetics was practised already by the ancient inhabitants of 

 India, less by the Greeks, but later by the Arabians. Pietro Ponce (died 1584) 

 was the first to give instruction in speech to deaf-mutes. Later, Bacon (1638) 

 studied the configuration of the mouth in the utterance of the various sounds; 

 Johann Wallis (1653) did the same, partly for the instruction of deaf-mutes, and 

 likewise Conrad Ammann (1692). Kratzenstein (1781) first produced artificial 

 vowels by fastening variously shaped resonators to a freely vibrating reed-appa- 

 ratus. Wolfgang v. Kempelen, of Vienna (1769-1791), constructed the first 

 talking machine. The voice-apparatus consisted of an ivory reed moved by 

 means of a bellows and striking upon leather. On the whole, the consonants 

 were well produced; the aspirates were produced by whistling and hissing reso- 

 nating tubes, the explosives by valve-like arrangements, R by a small rod dancing 

 on the ivory reed, etc. The vowels were produced by a megaphone, the cavity of 

 which was altered by hand; A (ah), O, U (oo) were readily produced, E (a) with 

 more difficulty, I (ee) incompletely. Air was forced through the entire apparatus 

 by means of a bellows, while the machine was "played upon" by the right hand 

 raising valves and the left hand changing the megaphone; Wolfgang v. Kempelen 

 stated correctly that tension of the vocal bands and narrowing of the glottis 

 take place together; he is to be credited with many other accurate observations 

 concerning the formation of articulate sounds. F. H. du Bois-Reymond gave, in 

 1812, a natural system of consonants. Robert Willis (1828) found that an elastic, 

 vibrating spring yields the vowels in the series U (oo), O, A (ah), E (a), I (ee), 

 in accordance with the pitch of its tone; also that the vowel-like sounds can 

 be produced in the same order by lengthening or shortening an artificial resonating 

 tube attached to a voice-apparatus. 



