254 EXPERIMENTAL PHONETICS. 



In soundinjj- <i the mouth is widely opened and the funduniental and 

 eight harmonics are produced; in the third series, on the contrar}', 

 there is only one harmonic sounded, which is more and more acute as 

 we pronounce the vowels in the order <ni^ u, and /. The vowels of the 

 second series, o, eu, and e, are transitional between the first and the 

 third. Thus we pass from a to ou by o, from a to f/ by ett, and from 

 a to l by e. 



Donders -' showed that the cavity of the mouth, as arranged for the 

 giving- forth of a vowel, was tuned as a resonator for a tone of a cer- 

 tain pitch, and that different pitches corresponded to the forms of the 

 cavity for the different vowels. This he discovered b}" the peculiar 

 noise produced in the mouth when the different vowels are whispered. 

 The cavity of the mouth is then blown like an organ pipe and by its 

 resonance reinforces the corresponding partials in the rushing wind- 

 like noise. Then the question was taken up by Helmholtz. ^ He 

 attacked it both by analysis and bj' synthesis. He analyzed the A'owel 

 tones by his well-known resonators, aided by his own singularly acute 

 ear, and he attempted to combine, by means of tuning forks, the tones 

 '\\liich he thought existed in a vowel, so as to reproduce the sound of 

 the vowel. In the latter part of the investigation he was by no means 

 successful. These investigations led Helmholtz to put forward in 

 succession two theories as to the formation of vowels. The first was 

 that, as in all musical instruments, the quality or timl)re of the vowel 

 depends on the fundamental tone, reinforced by certain partials or 

 overtones, of which a num])er are produced ])y the vocal cords along 

 with the fundamental tone, the reinforcement depending on the reso- 

 nance of the cavities a))ove tlie vocal cords. This theory was upset I)}' 

 the use of the phonograph. If a vowel is sung to the })honogiaph 

 while the cylinder is traveling at a certain speed, the vowel tone will 

 be reproduced with exactly the same quality if the cylinder is driven 

 at the same speed; l)ut if it is driven faster, then the quality t)f the 

 vowel will be changed, so much so as to be scarcely recognizaI)le. 

 M. Marey narrates that Donders and he first made this obser\;ition 

 when it so happened that the two savants were present in Paris at a 

 public demonstration of the phonograph soon after its invention. 

 Donders sang the vowel tones to the instrument, and then asked the 

 operator to vary the speed of the cylinder during reproduction. Tlien 

 the vowel (/ became o, and e ))ecame on. Thus while the phonograph 

 reproduces in a wonderful way the tones of musical instruments with- 

 out change of quality, it can not transpose \owel tt)nes without alter- 

 ing their character. This special character or quality can not. then, 



« Donders: De physiologie der Spraakklanken (1870). 



''Helmholtz: Ueber de Vokale. Archiv. f. d. ITolland. Beitr. 2, Nat. u. TIeilk. 

 (Utrecht, 1857). See other references given in Schiifer's Text-Book, vol. ii, p. 1217 

 (footnote). 



