3. Open the
Test Selector
and select the
ANSI
or
IEC
special test.
4. If OTOsuite is used without Noah, you can fill out the
Hearing Instrument
fields in the lower right corner of the
Standard Tests
screen. These fields are filled in automatically when you use OTOsuite with Noah together with the fit-
ting software for the hearing instrument.
5. Position the hearing instrument so that it is ready for testing, and switch it on.
6. If you wish to measure the
Battery Consumption
, make sure that you connect the battery simulator.
7. Close the lid.
8. If needed, click the arrow buttons in the
Measurements
table to include the individual tests you wish to perform.
9. Click the
Start
button in the top left corner of the
Measurements
table.
This will start a sequence of selected tests.
10. Make sure that you follow the on-screen instructions.
11. If you wish to redo an individual test, click on the
Start
button next to the test.
3.9.2
How to test the directional microphone
Directionality measurements as described in the hearing instrument test standards cannot be performed with regular desk-
top test chambers such as AURICAL HIT. Such measurements require large anechoic chambers. Small test chambers always
exhibit acoustic reflections that obscure the true directional behavior of the hearing instrument.
However, in AURICAL HIT you can make a functional test of the directional microphone in a hearing instrument. In this
test, the signal is first presented to the front of the hearing instrument and then to the back of the hearing instrument.
This is done automatically when you start a directional test. The signal used for this test is a flat spectrum Broad Band
Noise, band-pass filtered between 750 Hz and 5 kHz, and presented at 70 dB SPL.
Otometrics - AURICAL HIT
27
3 Testing hearing instruments
