Spectral analysis of auditory brain stem responses in perceptive hearing loss.

The Fourier analysis of auditory brain stem responses in 45 patients aged 19 to 56 treated because of perceptive hearing loss in Cracow ORL Clinic was carried out. The group consisted of: 15 patients with sudden deafness, 15 patients with Menier's disease and 15 cases with retrocochlear hearing impairment. In cases with recruiting cochlear hearing loss considerable and significantly extension of frequency range in brain stem responses was observed. Moreover, responses induced by stimulus intensity causing recruitment are identical for both ears as far as their shape and power spectrum is concerned, despite wide variety of responses caused by stimulus of different intensity. It is assumable that Fourier analysis of auditory brain stem responses gives possibility of objective evaluation of subjectively determined recruitment syndrome.