Evening star., 1923-06-10
Radio Tube May Lead to Cure
For Deafness, Is Latest Claim
ssAudiOmeter" Determines Volume and
Pitch of Sounds AudibIe to Normal
and Abnormal Ears.

calculated from the electrical energy
input into the tubes. Hence the air
pressure produced on the ear drums
when a tone Is being screened can be
calculated.
Thus we now have available an
electro mechanical instrument capa-
BILE OF producing. within itself. pure
tones throughout the entire range Of
sounds which the human ear Is ca
pablo of detecting; tones of any de-
sired pitch and of any desired in
tsnsity or loudness.
1t produces unatded its own cleo
trical oscillations or vibrations
through the functioning of the tubes
and the associate circuit. and these
electrical vibrations are transformed
into sound vibrations of correspond
ing frequency or pitch by means of
the telephone receiver.
Many Ear Tests Made.
BY the employment of the audio-
meter IN conjunction with the ears"
of a large number of men and women
in their laboratories, the telephone
engineers have explored and investi
Pated the whole auditory e~uSatinn
area, or the entire range OF sounds
percSptI BILE to tnr nuHIi:i- g..
As Il result, it has been estahliSHH -"
that there are 100000 individual pure
tones which can be made percepLlpIe
10 the human ear, a pure tone being
defined as one in which there is no
mixture of other tones and is Specf-
fed by its pitch and loudness. These
correspond to sound waves of fire.
quenctes varying from about 16 cycles
per second for sounds of extremely
low pitch TO about 10000 cycles for
sounds of extremely high pitch.
OF these 4e5.Q00 pure tones 100000
Individual tones or sounds can ordi-
narily be made audible to the average
normal ear; the average ear being
less sensible to the other 10000
tones which correspond to sounds of
extremely low and extremely high
pitch; relatively greater expendi-
ture of energy being required to pro-
duce such sounds of sufficient in
tenSity to make them audible. and
the impact OF such sound waves on
the ear drum causing annoyance to
the listener as a result OF their hurt-
Ing the ears
Valuable Medical InstruInent.
Thus. a result of the work of
the telephone engineers, We now have
availab BILE accurate knowledge of the
entire field OF audible sounds; their
frequency in cycles and correspond
ing pitch in tones; the energy re-
quired TO produce any or all OF
them to any desired intensity; the
minimum intensity at which they
become audible to the normal ear and
the maximum intensity at which they
become annoying by hurting the nor
NAL ear; and the range of tones and
man speech and which are otherwise
made perceptIble to our ears in the
world in which we live.
AS q result of the functionins OF
the vacuum tube and the telephone.
these sounds can be produced, record
ed and measured.
BY subiecHng q candidates sense
OF hearing to a comparative test, his
hearing powers can be analysed. His
degree of deafness. If any, can be de-
ternined, and any peculiaritieS Of the
inner ear as regards its perception
or lack OF perception OF the individual
tones can be determined and as d re-
suit his affiictton may possibly be
aIneliorated or removed by suitable
medical OF surgical treatment
The audiometer is, therefore, a val
uablt medical instrument, especially
for use in hospitals which specialize
in ear troubles
Useful In Csart Cases.
1t is also useful device for en-
ployment in court cases where the
question Of the degree of deafness is
involved. particularly as regards the
obtaining of automobile licenses, with
respect to which large variations now
exist between standards OF hearing
set UP by various doctors in the
different parts OF the country.
1t should also be a desirable ad-
junct In our 81 Dis because the lack
OF PROGRESS on ,ie part of delinquent
students may sometimes be due more
to impaired or defective hearing when
attending classes in the lecture
rooms. and OF which the instructor
or student may not be aware, than
to any other cause.
The audiometer, in short, provides
us with an extremely useful instru-
ment for medical, legal. and instruc-
tional purposes and 1t may eventually
result in u clearly defined (though in
tangible) legal standard" of nor
NAL hearing being enacted into law
in some such manner that we now
have legal standards Of weights and
measures in tangible form at the Bu-
reau of Standards.
Copyrighted. 1873 oist Century Press1