MIDIMATE 602 & 622 Diagnostic Audiometers
20
6
Special Tests
To go to the
Select special Test
menu, press
Menu
until the
Select Func-
tion
menu is displayed and then press
Softkey 3
,
Special
.
6.1
The SISI test
The SISI test (Short Increment Sensitivity Index) shows whether a patient can detect
small variations in intensity lasting 200 ms. The SISI test is not a recruitment test. A
patient who scores 60% or better for frequencies above 1000 Hz or in some cases
down to 250 Hz may have cochlear problems. Patients with normal hearing, middle
ear diseases or nerve hearing loss will score up to 20% at all frequencies.
To make the SISI test, do as follows:
1.
Connect the patient response handswitch, the headphones, the optional monitor
headset (or the optional monitor adaptor with talkover microphone and monitor
loudspeaker), and the optional patient talkback microphone.
2.
Switch on the electric power supply.
3.
Place the patient, facing away from the MIDIMATE 602/622, in a sound-cabin, if
available.
4.
Press
Menu
once or twice to display the
Select Function
menu.
5.
Press
Softkey 3
,
Special
.
6.
Select
SISI (A) L
from the
Select special Test
menu by pressing
Soft-
key 1
.
7.
Select
Left
by pressing
Softkey 1
or
Right
by pressing
Softkey 2
.
8.
Instruct the patient to activate the patient response handswitch every time a short
increment in level is heard.
9.
To demonstrate the test to the patient, turn the
Hearing Level
wheel until the
stimulus tone (shown above
Softkey 3
) is 40 dB or more.
10.
If the display does not show
1-5dB
, (the 5 dB default increment), toggle
Softkey
2
until it does.
11.
Press the
Tone Switch
to begin the demonstration.
12.
Make sure that the patient has understood the instructions: the
Response
indi-
cator lights up when the increments in stimulus tone are displayed above
Soft-
key 3
. The increments are not audible in the monitor headset.
13.
Stop the demonstration by turning the
Hearing Level
or
Frequency
wheel.
14.
Reduce the stimulus tone to 20 dB.
