400 THE EAR
understand either of the people talking. If he is able to hear and follow, it will
indicate that he really does not hear on one side.
3. The patient closes his good ear with a finger. The surgeon now repeats
words and numbers to him, at first in a low voice and then in progressively
louder tones. If, when one has reached a pitch at which he should be able to
hear the words with the sound ear even though tightly occluded he still states
that he cannot hear, one knows at least that he is an intentional malingerer.
4. Lombard's test depends upon the fact that to the normal man the sound
of his own voice is necessary to the proper regulation of its tone and intensity.
The Barany noise apparatus is adjusted in the patient's sound ear, and its
machinery started in order to accustom him to its grating noise. He is given
a book, and told to read aloud in his natural voice, and not to stop reading
when the instrument is set in action. As soon as the noise begins, a man whose
opposite ear is profoundly deaf will at once raise his voice and, if his unilateral
deafness is absolute, may literally shout. The malingerer, on the other hand,
claiming a one-sided deafness which is not real, will continue to read in an
even tone or in a tone only slightly elevated. Many malingerers, when asked
to co-operate in this test, pretend that they are unable to read. When admitted
to hospital, however, they may be seen surreptitiously reading the daily papers
5. Tealys method. The patient is again blindfolded, and in a friendly
manner told that if he is really deaf there is no disposition to overlook it. But
he is also warned that if he tries to show dishonesty he is sure to be 'tripped
up'. Air-conduction is tested and, of course, is negative. The Weber test is
then used, and usually (though reluctantly) he hears the fork in the deaf ear.
Bone-conduction over the mastoid process is next tested, and again he
admits hearing the fork. The real test is now used. After saying one wants to
try the last test once more, a non-vibrating fork (or lead pencil, flat end) is
placed over the process to make him think he is being tested in the same
manner, but at the same time a vibrating fork is brought up close to the
auricle with the other hand to test the air-conduction. If he is simulating
deafness he will, of course, answer that he hears the fork, and the fact of a
normal path of air-conduction is established. If he is really deaf, he will, of
course, not hear the vibrating fork.
The pure tone audiometer facilitates detection of malingering. The sounds
of the audiometer being loud enough to carry to the opposite ear, if a listener
with unilateral deafness does not admit such 'shadow' hearing, he is a
malingerer; while marked variations in repeated threshold readings must
arouse suspicion. Some of the tests for which tuning-forks are employed can
be performed equally well or better with the audiometer. Impedance audio-
metry, using the stapedial reflex, can objectively demonstrate the presence
of hearing. Evoked response audiometry also has a place.
ADDS TO HEARING
1. Electrical Hearing Aids. These are the most widely used aids to hearing
and consist of a microphone, an amplifier and a receiver or ear-piece. The
amplifier and microphone are usually contained in the same unit which may
be warn on the body or in a much smaller unit behind the ear. In the case of a
body-worn aid the sound is delivered to the ear by a wire which is connected
to a receiver which fits into the ear. In a behind-the-ear aid the receiver is in