Operating Instructions MA 53
Geba_MA53_e_13a.doc
13 851 430/3 11/11
4 Pure tone audiometry
4.1 Air Conduction (AC) Testing
In the hearing threshold test, the hearing threshold of the
patient is measured in comparison with the normal
hearing threshold for air conduction. The test is started on
the ear with better hearing.
The patient should sit at a distance of at least 1 m from
the device.
Eliminate any obstructions which will interfere with the
placement of the earphone cushions on the ear (i.e. hair,
eyeglasses).
Ensure the headphones are put on correctly: Red side on the right, blue side
on the left. Adjust the headband of the headphones so that the receivers are
at the correct height (the sound output grid exactly facing the ear canal).
Start with the “better” indicated ear at 1 kHz. (After switching on, the
frequency is automatically set to 1 kHz.) In the following example we assume
that the left is the “better” ear.
Set the receiver selector
to AC and the signal selector
to TONE.
Set the left level control knob
to a value just below expected hearing loss.
Explain to the patient that he should press the button of the patient response
switch if he just hears the test tone.
Press the STIM bar
for a certain
time to present the test tone. The
STIM LED
should light on.
If the patient hears the test tone,
the patient response display lights
red. In this case decrease the level
with the level control knob
.
Proceed with presenting the test
signal as described before.
If the patient doesn’t hear the test
tone, increase the level with the
level control knob
. Proceed with
presenting the test signal as
described before.
Picture 11 Headphone
Picture 12 MA 53 controls and display for air conduction
threshold test of the left ear
Содержание MA 53
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