[Modification of precocious evoked auditory potential amplitudes observed in tinnitus].

Brainstem evoked response audiometry has been performed in 139 patients complaining of tinnitus, unilateral or bilateral. Amplitudes of I, III, V waves and the amplitude relations I/III, I/V, III/V have been compared with those obtained in a normal population (n = 20). Amplitudes of waves I and III decreased according to their localization: decrease of left I and III for left tinnitus, decrease of left I and right III for right tinnitus, and for I and III both left and right for bilateral tinnitus. Recording of brainstem evoked response before any therapeutical treatment, especially study of amplitudes, could therefore provide information an localization of tinnitus.