HARMONIC ANALYSIS OF CERTAIN VOWEL SOUNDS. (Gil 
The sound @ is produced mainly by the reinforcement of a single partial tone, 
generally lying in the region a to a’, The sound 6 requires, at least, two strong 
partials. When there are only two they lie in the region between g and /”. 
Possibly the upper limit may extend even higher than /” with a tenor or a 
woman’s voice. Other tones than the prime are reinforced in the sound 6 over 
a region covering nearly two octaves, namely, from /” to g. 
This great range over which reinforcement extends must be a distinguishing 
mark of 6 as compared with @, perhaps the distinguishing mark. We have seen 
that when @ and 6 were sung on bb by voice 1, 6 consisted of a strong first and 
second partial, 7 of a weak first and strong second. The pitch of the most 
strongly reinforced tone in both was by’, the “ characteristic tone” of 6. But, in 
point of fact, this was much more strongly reinforced in the @ than in the 0. 
The characteristic mark separating 6 from « cannot therefore have been the 
prominence of the tone b,’: it must rather be sought for in the fact that for @ 
this tone alone was reinforced, whereas for 6 the prime was reinforced to some 
extent also. Again, when voice 5 sang 6 and @ on the same note, by, it gave a 
strong prime and second for 6, but a strong prime only for @ Here, too, the 
distinction must lie in the extent over which the reinforcement acted, for the 
difference of average pitch of reinforcement was positively greater between the 
two a's than between either of them and either of the 6’s. The maximum reson- 
ance of the « sung by voice 5 on bb was a whole octave above that of the @ 
sung by voice 1 at the same pitch; and, if we take the pitch of maximum 
resonance of the 6’s as bp, then the pitch of maximum resonance for 6 and a sung 
on bp by voice 1 was precisely the same. The argument is not in any way 
weakened by saying that the « of one voice was not the same vowel as the @ 
of the other. Identically the same it cannot have been ; nevertheless, on higher 
or lower notes, the two voices agreed as to the composition of #, and generically 
the vowels were certainly the same. Speakers and hearers were unconscious of 
any generic change in the vowel sound # when the pitch of maximum resonance 
of the oral cavity rose suddenly by a whole octave. The evidence appears con- 
clusive that the prominence of a single partial tone due to the reinforcement given 
by a single proper tone of the oral cavity is insufficient to characterise a vowel. 
It is equally clear that even in the case of the human voice, in singing or 
speaking, a given vowel does not simply produce a certain group of relative 
partial tones independently of absolute pitch. Possibly, indeed, the ear might 
recognise a single tone with a feeble accompaniment of upper partials as a sort 
of « below the region within which the human voice produce the simple form of 
a. Thus, HELMHOLTZ says that a bp fork when sounded alone gave a very dull 
z, much duller than could be produced in speech ; the sound became more like 
a“ when the second and third partials were added feebly. This tone is an octave 
below the pitch where voice 1 ceased to give the simple form for 7. Similarly, 
