AUDITORY EVENT-RELATED POTENTIALS IN CHRONIC TINNITUS PATIENTS WITH NOISE-INDUCED HEARING-LOSS

In order to explore a possible deficit in auditory central neural acti vity in tinnitus with noise induced hearing loss (NIHL), auditory even t related potentials (ERP) and reaction time (RT) were recorded (measu res of central processing) from tinnitus patients (N = 12) and hearing and age matched controls (N = 12). Testing procedure included oddball paradigms and 1 KHz repetitive stimulus, as well as click-induced bra instem auditory evoked potentials (BAEP). ERP amplitudes (waves N1, P2 and P3) in tinnitus patients were significantly lower than in control s in all testing paradigms. No differences were found in ERP peak late ncies, BAEP, RT, or response scoring. The lower ERP amplitudes may ind icate attenuated or 'abnormal' auditory central processing in NIHL tin nitus patients. It is suggested that this dysfunction reflects an adap tive brain process response to the tinnitus and points to auditory cen tral involvement in tinnitus sensation.