OF ARTS AND SCIENCES. 271 



XX. 



CONTRIBUTIONS FROM THE PHYSICAL LABORATORY OF THE 

 MASSACHUSETTS INSTITUTE OF TECHNOLOGY. 



XXXTX. — ON SOME EXPERIMENTS WITH THE PHO- 

 NOGRAPH, RELATING TO THE VOWEL THEORY 

 OF HELMHOLTZ. 



By Charles R. Cross and George V. Wendell. 



Presented May 24, 1892. 



The value of the phonograph as an aid in the study of the 

 theory of vowel tones was recognized almost immediately upon 

 the invention of that instrument, and it was employed for this 

 purpose as early as 1878 hy Messrs. Jenkin and Ewing,* and 

 also hy Dr. C. J. Blake in connection with one of the present 

 writers. The experiments of the last mentioned observers were 

 designed to aid in the solution of the question whether it is a fact, 

 as assumed hy Helmholtz, that each vowel possesses a distinctive 

 character due to the presence of a particular tone or tones, which 

 are the resonance notes of the mouth cavity when shaped for the 

 utterance of the corresponding vowel. The method employed, and 

 the results obtained were described in a letter to Nature (Vol. 

 XVIII. p. 93), so that a brief reference to them will suffice. 



The plan followed was to speak a vowel into the mouthpiece of 

 the phonograph when the cylinder was revolved at a certain rate, 

 and then to reproduce the tone with a varying rate of revolution, 

 both faster and slower than that used when the record was im- 

 pressed upon the cylinder. Any particular resonance note, if pres- 

 ent, would then have its pitch raised or lowered, and presumably 

 the vowel sound would be correspondingly altered. 



This was found to be the case, the vowel apparently changing 

 with change of speed of the cylinder. For example, the vowel 6 



* See Nature, Vol. XVII. p. 384 ; Trans. Roy. Soc. Edinburgh, Vol. XXVIII. 

 p. 745. 



