Acquisition and analysis of brainstem auditory evoked responses of normal and diseased subjects by spectral estimation.

Human brainstem auditory evoked responses (BAERs) are sensory evoked potentials that can be recorded within a few milliseconds following a transient acoustic stimulus (click signal). This paper suggests a novel technique to clearly demarcate normals and patients with complaints of vertigo and deafness by computing hitherto unused power spectral parameters from the BAER signals recorded on them. The BAER spectrum of normal subjects contains three main frequency components, i.e. low-, mid- and high-frequency components around 100, 500 and 1000 Hz, respectively, which is not so in the case of diseased subjects. The spectral parameters, i.e. the mean power frequency, median frequency, the ratios of the integrated power at dominant frequencies to that of the total power in spectrum and change in spectral power (CP) between these dominant frequency components are used to classify the recorded BAER signals into those of normals and the patients, and aid the clinician in quick and better diagnosis. The ranges of CP are estimated for the different groups and appear to be the most dominant parameter in the classification of the BAER signals.