MIDIMATE 602 & 622 Diagnostic Audiometers
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3.
If you are using recorded speech for testing, a high-quality talk back microphone,
amplifier and headset are required. If they are not used, there may be discrimi-
nation loss because it will be difficult to hear the patient repeat the words. The
microphone should be uni-directional and should be placed close to the patient.
4.
The recorded speech material used for the test must have a stated relation with a
recorded calibration signal.
5.
Select User Test 3 (§3.1) instead of step 0, unless the default setting has been
changed, or press
Softkey 1
,
Tape (CD)
, instead of
Softkey 2
in step 0.
6.
Instead of doing as in step 0, start the tape recorder or CD player. Keep pressing
the
Tape 1
pushkey on the
Level
panel and turn any of the three rotary wheels in
order to obtain a peak deflection of 0 dB on the
Stimulus
VU indicator.
The procedures for threshold and discrimination testing with recorded speech are
similar to those described in §5.1.2 and §5.1.3.
5.3
Testing with Free-Field speech
For Free-field speech testing use loudspeakers (such as 8–02–450) and a two-channel
power amplifier such as PA 210 (8–02–240) instead of headphones to present the
speech to the patient. The measured thresholds will be influenced by:
•
The distance from the loudspeakers to the patient;
•
The acoustic absorption of the walls of the test room;
•
Ambient noise.
Free-field speech testing is especially useful for fitting hearing aids, particularly those de-
signed to compensate for perceptive-type hearing loss and discrimination loss. With masking
applied, it is also useful for testing children who dislike wearing headphones.
To set up a free-field tone test, do as follows:
1.
Press
Menu
to select the
Select Function
display.
2.
Press
Softkey 2
to select
Speech
.
3.
Press
Softkey 3
to select
F.F.
4.
Press
Softkey 1
to select
Left
.
5.
Press
Softkey 1
to select
Tape (CD)
.
6.
Press
Softkey 1
to select
No Mask
. If masking is required, you can select
WN
(
Softkey 2
),
SN
(
Softkey 3
) or
Ext
(
Softkey 4
).
7.
Adjust the level of the stimulus as described in step 0 in §5.2.
