Directionality Measurements - Interacoustics Affinity 2.0 Additional Information

2.0
Affinity Additional Information
2.7.7

Directionality Measurements

Unwanted noise will inevitably turn up in daily life situations. Fortunately, many digital hearing aids have
directional microphones that suppress noise coming from some directions while maintaining a good
sensitivity to sounds coming from another direction. This effect can be measured in the real-ear.
Place the client in front the REM loudspeaker. First a response curve/frequency response is recorded for
sounds coming from the front. After this turn the client around facing the opposite direction and a similar
curve will be recorded for sounds coming from the back. Then the second curve is subtracted from the first
and results in the directionality curve.
If preferred the directionality test can also be performed using a free field speaker as the back speaker.
Test procedure:
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1) Open the REM440 module by selecting the REM tab.
2) Select a test in the List of Protocols. If a customized test setup is not created the REM440 will
automatically pick a standard test.
3) Explain the procedure to the client.
4) Perform otoscopic examination.
5) Mount the probe tube on the in-situ headset and place it on the client who should be seated in ½-1
meters distance from the speaker.
Ensure that the probe tubes are calibrated before placing them in the ear canal (see section 0 about
tube calibration).
6) Carefully insert the hearing aid without moving the probe tube. Ensure that the instruments are
switched on.
7) If fitting an open hearing aid solution, perform Calibrate for open fit (see section 0)
8) Click on the Directionality button if it is not already marked automatically.
A right click on Directionality button allows you to enter the Settings menu or Change colour of the
curve.
9) Check that the information about client, fitting prescription and hearing aid to the right are correct.
10) Ensure that the correct Ear is selected
11) Choose the preferred Stimulus in the
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corresponding dropdown list
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