MIDIMATE 602 & 622 Diagnostic Audiometers
12
6.
Fit the headphones on the patient, with the red phone on the right ear.
7.
If required, test the level of the operator’s monitor or talkover microphone on the
patient. If needed, adjust by pressing and holding down the
Microphone
key in
the left-hand
Level
section of the front panel, or the
Talk Over
key and turning
any of the rotary wheels. The
Stimulus
indicator shows the percentage used.
8.
Toggle
Shift L/R
to select the ear with the better hearing to be tested first. The ear
selected for testing is shown on the display above
Softkey 3
.
9.
Turn the
Frequency
wheel to set the stimulus frequency shown on the display
above
Softkey 1
. Testing normally starts at 1000 Hz.
10.
Toggle
Softkey 2
to
P
if pulsed tone is required.
11.
To present the stimulus tone to the patient’s test ear, press the
Tone Switch
,
which is the large key below the
Hearing Level
wheel. The
Stimulus
indicator
lights to confirm that the tone is presented and displays the intensity as long as
the
Tone Switch
is held down.
12.
Turn the
Hearing Level
wheel to change the stimulus intensity until the patient’s
threshold is found for the current frequency (displayed above
Softkey 1
), and
read its value from the display above
Softkey 3
.
13.
If
Store
is set up, press
Softkey 3
twice to store this value (MIDIMATE 622
only).
14.
Repeat the test at the next frequency. Testing is usually done at increasing fre-
quencies until the highest frequency is reached, and then to test at the frequencies
below 1000 Hz in descending order.
15.
Repeat the test for the poorer ear.
4.1.3
Testing patients with large threshold differences
If the difference between the thresholds in the two ears is greater than 40 to 60 dB, do
as follows:
1.
Press
Menu
to display the
Select Function
menu.
2.
Press
Softkey 2
to select
Air
, which presents Narrow Band Noise (masking) to
the better (contralateral) ear.
3.
Use
Softkey 4
to toggle masking
On
.
4.
Turn the
Masking Level
wheel to set the masking level shown on the display
above
Softkey 5
.
5.
Cooperate with the patient to determine the threshold for Narrow Band Noise for
the contralateral ear.
6.
Set Masking to a level 15 dB above this threshold.
7.
Continue to apply masking to the better ear. Present a tone to the poorer ear at
the hearing level that was previously determined to be the tone threshold with-
out masking.
