PROCEEDINGS. 
539 
Mr. J. C. Gordon made a communication entitled Notes on 
the Discovery and Development of Hearing in Certain Deaf- 
Mutes. 
[Abstract.] 
The pupils in our schools for deaf-mutes have been, before admission, 
with rare exceptions, under the care of physicians and aural surgeons, 
who have pronounced them incurably and hopelessly deaf. Instructors, 
until recently, have acquiesced in the diagnosis furnished, and have 
referred phenomena indicative of partial hearing, either to acuteness of 
tactile sensation or to sense-impressions, too rudimentary for use or im¬ 
provement. 
Experiments by the writer years ago convinced him that the prevalent 
opinion was a generalization too sweeping, and that a large percentage of 
so-called deaf-mutes were fit subjects for auricular training and develop¬ 
ment. 
The honor of initiating experiments leading to important results be¬ 
longs to Mr. J. A. Gillespie, of Omaha, who began in the Nebraska Insti¬ 
tution, with selected pupils in 1880, progressive exercises in auricular 
development, which were carried to a successful conclusion. This led to 
the consideration of the subject by conventions of instructors of the deaf 
and to the appointment in 1884 of Professors A. G. Bell, F. D. Clark, and 
the writer as a committee to make thorough investigation of tests of hear¬ 
ing and other phases of the subject. This committee presented in 1885, 
through the American Annals of the Deaf , a preliminary report, and its 
members still hold in reserve much interesting matter for further inves¬ 
tigation and study. 
• The writer here gave an account of the auditory apparatus, with reasons 
for thinking that a standard test for hearing, approaching to a standard 
test of vision in scientific exactness, is not attainable. After referring 
to various acoumeters, and to the tests and methods of expressing re¬ 
sults approved by the American Otological Society, the telephonic audi¬ 
ometer devised by Professors Clark and Bell was described. This ap¬ 
paratus consists of a Bell receiver in circuit with the movable coil of 
an “ induction balance,” the fixed coil of which is connected with an 
ordinary magneto-electric machine. The rapid revolution of the arma¬ 
ture produces a very loud sound in the telephone when the coils are 
together, which diminishes as the induced current becomes weaker by sepa¬ 
rating the coils, until it is finally inaudible. Provision is made for cutting 
off the sound at will without the knowledge of the subject tested. The 
vanishing point of the sound, or the initial point as the coils approach, 
as read on a centimeter scale measuring the separation of the coils, is 
taken as the measure of audition. This vanishing point in persons whose 
hearing is good ranges, say, from 55 to 87 centimeters, and is rarely the 
same for both ears. Though this apparatus was suggested by Hughes’ 
sonometer, important modifications are apparent which make it simpler 
