Testing With Free-Field Speech - otometrics Madsen Midimate 602 Quick Manual

MIDIMATE 602 & 622 Diagnostic Audiometers
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.
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