Special Audiological Tests
Symptoms associated with hearing loss like giddiness, tinnitus, vomiting, nausea, positional vertigo, imbalance indicates the need for differentiation of cochlear versus retrocochlear pathology. Thus site of lesion special audiological tests are required. These tests are –
Tone Decay Test (TDT)
It is based on auditory adaptation phenomenon. In this the patient is instructed to raise hand till the tone is perceived at the same intensity level. It is a powerful diagnostic procedure for identifying Retrocochlear Pathology.
Short Increment Sensitivity Index (SISI)
It is based on Difference Limen for Intensity (DLI). In this ears ability to detect very small changes in intensity is measured. Individuals with cochlear loss are able to detect small increments in intensity (as small as 1 dB). This is a powerful diagnostic test for identifying Cochlear Pathology.