Welcome to the product training for AC40 audiometer. On this page you will find an overview of all the available training materials and support.
The short increment sensitivity index (SISI) test measures the ability to recognise 1dB increases in intensity during a series of bursts of pure tones presented 20dB above the pure tone threshold for the test frequency. It can be used to differentiate between cochlear and retro cochlear disorders, as a patient with a cochlear disorder will be able to perceive the increments of 1dB, whereas a patient with a retro cochlear disorder will not.
The SISI test should be conducted at 20dB SL for all frequencies tested. If the patient does not manage to get a high score on the SISI test, this could be indicative of retro cochlear damage.