Short Increment Sensitivity Index - Interacoustics Affinity 2.0 Additional Information

2.0
Affinity Additional Information
1.7.9

Short Increment Sensitivity Index

SISI is designed to test the ability to recognise 1 dB increase in intensity during a series of bursts of pure
tones presented 20 dB above the pure tone threshold for the test frequency. It can be used to differentiate
between cochlear and retrocochlear disorders as a patient with a cochlear disorder will be able to perceive
the increments of 1 dB, as where a patient with a retrocochlear disorder will not.
Required Items:
•
The Affinity hardware
•
Licensed AC440 Audiometry module within your Affinity
•
Calibrated Headphones or insert phones
•
A patient response button
Test Procedure:
1) Open the AC440 and enter the SISI screen by selecting Menu | Tests | SISI.
2) Select Tone or Warble Tone in the channel 1 input list. If needed masking can be selected in the
channel 2 input dropdown list.
3) Select headphones or inserts in the channel 1/channel 2 output lists
4) Set the input level to 20 dB above threshold using the dB HL Decrease/Increase channel 1/channel
2 buttons or arrow keys on the PC keyboard.
5) Explain to the patient that they will now hear a series of tones. If suddenly one tone seems louder that
the other ones the response button should immediately be pushed.
6) Select the preferred type of SISI test. Setting the system to 1 dB increments is considered to be the
classical SISI. If the patient is able to hear these increments and scores high, cochlea damage is
likely. You may also choose 0 dB, 2 dB, or 5 dB increments.
If the patient does not manage to get a high score on the SISI test this could indicative of retro-
cochlear damage.
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SISI requires an additional software license.
13
2.0
hardware with SISI functionality
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