Special Test

The Short Increment Sensitivity Index (SISI) test is an audiometric test used to assess a person's ability to detect small changes in the intensity of a continuous tone. It is primarily employed to evaluate the functioning of the auditory nerve, especially in cases of retrocochlear pathology (abnormalities beyond the cochlea, involving the auditory nerve or central auditory pathways).

Purpose:
Assessment of Auditory Nerve Function:

• SISI is used to detect abnormalities in the auditory nerve or central auditory pathways.

Identification of Recruitment:

• Recruitment is an abnormal increase in loudness perception. SISI can help identify or rule out recruitment.

Procedure:
Pure-Tone Audiometry Baseline:

• The individual undergoes standard pure-tone audiometry to establish baseline hearing thresholds.

Continuous Tone Presentation:

• A continuous tone is presented at a fixed frequency and intensity.

Incremental Increases:

• Small, short-duration increases in intensity (usually 1 dB) are introduced during the presentation of the continuous tone.

Response Recording:

• The individual indicates whether they perceive a change in loudness during each incremental increase in intensity.

Scoring:

• The test results are scored based on the number of incremental intensity changes the individual correctly perceives.

ABLB TEST

The Alternate Binaural Loudness Balance (ABLB) test is a diagnostic tool used to assess subjects with unilateral hearing loss. It’s a subjective test that relies on the patient's ability to compare the loudness of sounds presented to each ear to indicate where they are equal. It is commonly used to identify recruitment/hyperacusis in the poorer ear of asymmetrical hearing losses.