Masterpieces of Science 



engaged concerning the musical relations of 

 vowel sounds. When vocal sounds are whis- 

 pered, each vowel seems to possess a particular 

 pitch of its own, and by whispering certain vow- 

 els in succession a musical scale can be distinctly 

 perceived. Our aim was to determine the 

 natural pitch of each vowel; but unexpected 

 difficulties made their appearance, for many of 

 the vowels seemed to possess a double pitch 

 one due, probably, to the resonance of the air in 

 the mouth, and the other to the resonance of the 

 air contained in the cavity behind the tongue, 

 comprehending the pharynx and larynx. 



I hit upon an expedient for determining the 

 pitch, which, at that time, I thought to be original 

 with myself. It consisted in vibrating a tuning 

 fork in front of the mouth while the positions of 

 the vocal organs for the various vowels were 

 silently taken. It was found that each vowel 

 position caused the reinforcement of some par- 

 ticular fork or forks. 



I wrote an account of these researches to Mr. 

 Alex. J. Ellis, of London. In reply, he informed 

 me that the experiments related had already been 

 performed by Helmholtz, and in a much more 

 perfect manner than I had done. Indeed, he 

 said that Helmholtz had not only analyzed the 

 vowel sounds into their constituent musical ele- 

 ments, but had actually performed the synthesis 

 of them. 



He had succeeded in producing, artificially, 

 certain of the vowel sounds by causing tuning 

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