Vol. 8, 1922 
PHYSICS: J. P. MINTON 
275 
one, is a result of further cooperation with some of the ear speciaHsts of 
Chicago. 
It is generally accepted among medical men that the purpose of an end- 
organ is to lower the threshold of perception of certain sensations. In 
the case of the ear, the complicated internal-ear structure is not only for 
the purpose of lowering the threshold of audition, but, according to all 
the mechanical resonance theories of pitch perception, it is also for the 
purpose of making possible the phenomenon of this perception. Data 
which have now been collected show with much certainty that these 
resonance theories are untenable and it is the purpose of the present 
paper to present some of these data. The results seem to show clearly 
that the sole purpose of the mechanical structure of the internal-ear is 
to lower the threshold of audition and that the power of pitch perception 
is a property of the nerves including their endings. According to this 
view, then, the power of pitch perception is in no way associated with the 
actual mechanical structure of the cochlea. 
2. Experimental Results. — The details of the method of testing were 
described in the paper to which reference has already been made and 
these need not be discussed in this place. Many cases of nerve-deafness 
have been examined but only those that have a direct bearing upon the 
purpose in mind will be presented. 
a. One of the most interesting set of curves for nerve-deafness is that 
shown in figure 1. This set is for a person 45 years of age. The upper 
curve was taken in December, 1920. The lower curve for the same ear 
was taken in March, 1922, so an interval of sixteen months had elapsed. 
The curves show that the ear functioned in a normal manner up to 
1000 d. V. So, as pointed out in the previous paper, we know that no 
deficiency in hearing exists because of middle-ear trouble. During the 
period of sixteen months the impairment of hearing has become quite 
marked; requiring about 665,000 times as much current through the re- 
ceiver for the threshold of audition at 3000 d. v. as is required by a normal 
ear. The minimum of the earlier curve has shifted from 3300 d. v. to 
3000 d. V. during the interval. The range in frequency for which a de- 
ficiency in hearing exists includes lower pitches than were included in the 
first test, and, moreover, over the affected range the impairment is much 
more marked than indicated by the first curve. It is almost incredible 
that a person could be as deaf as indicated by these curves at some pitches 
and still have normal hearing at other frequencies. 
In the case of the patient under discussion, near the threshold of audi- 
tion at the higher pitches, say in the region of 3000 or 4000 d. v., the tones 
would break through, so to speak ; they would be heard as pure tones with 
much intensity. A moment later it seemed as though the supply of nerve 
energy had been exhausted and the sensation of a pure tone would change 
