583 
of Edinburgh, Session 1877-78. 
and Helmholtz seem all to consider that a certain absolute pitch is 
characteristic of each vowel. 
[Note. — May 24. — Since the above communication was made to 
the Society, the authors have improved their phonograph, and also 
their apparatus for enlarging the record embossed on the tinfoil. 
For this reason they have substituted in the figures shown better 
curves than those which were originally presented to the Society. 
Subsequent experiments with the improved instrument also render 
it desirable to add a few words to the statement made in the text as 
to the effect of altered speed in the quality of the sounds given by 
the phonograph. The original experiment consisted in speaking 
the set of vowel sounds, A, E, I, 0, U (pronounced in Italian 
fashion), to the phonograph, and then listening to the sound given 
when the instrument was run at various rates. The vowels were 
observed to maintain their relative places, so as to form the complete 
series in which each individual sound was by contrast at least 
recognisable as the vowel which had been spoken. This experiment 
has since been frequently repeated with perfect success. Again, if 
a single vowel sound, such as “ oh,” be sung to the phonograph at 
an ordinarily high pitch, it will be found to remain oh through a 
considerable range of speeds ; but the oh whose pitch has been 
raised by quickening the phonograph seems to the authors brighter 
than the oh sung by the human voice at a correspondingly high 
pitch; that is to say, it resembles “awe” to some extent. Similarly 
the spoken “ aive ,” when accelerated, passes into a sound like ah. 
The change appears to be greater with some vowels than with others, 
and also to depend partly on the pitch at which the vowel has been 
originally sung. The instrument is, however, even in its present 
improved form, not well adapted for testing any fine gradation of 
the quality of sound. Although the authors now feel unable to 
speak with any confidence as to change of quality produced by a 
change of speed, they consider it proved that the vowels, A, E, I, 
0, U, remain distinguishable by contrast when all their constituents 
are simultaneously raised or lowered to a considerable extent, but 
they do not consider that the phonograph is as yet sufficiently perfect 
to enable them to judge how far the definition of constant quality 
suggested in § 3 below would or could be accepted by the ear.] 
