Short Increment Sensitivity Index (SISI)

The SISI test is a diagnostic tool for cochlear pathology. The test is based on recruitment, a condition that exaggerates your perception of sound.

How does it work? Well, a series of SISI tests are run that begin at 20 dB S.L. and increase in steps of 10 dB until a 100% SISI score is obtained. In individuals with no sensory deafness, the score rises gradually with an increasing carrier tone to reach 100% at 60 dB above threshold. In individuals with sensory deafness the 100% is reached with carrier tone at only 30 dB above threshold.

The test acts as a tool to identify the site of lesion (tear) in the ear. It is always better to get tested as early as possible since early diagnosis makes for better treatment outcomes.