Auditory P300: Selective Attention to 2 KHZ Tone-Bursts in Patients with Idiopathic Subjective Tinnitus

Objective: To study whether a group of idiopathic subjective tinnitus (IST) has abnormal changes in auditory P300 and to compare these results with normal subjects. Design: AuditoryP300 was done to thirty two patients with idiopathic subjective tinnitus and they were compared to normal. The elicited auditory P300 event-related potentials (ERPs) were analyzed in terms of peak amplitude and latency of the P300 waveforms. Basic audiological assessments that include pure tone audiometry and immittancemetry were done to the whole study group. Results: The results showed that while P300 peak amplitudes were overall reduced for idiopathic subjective tinnitus but it was varied individually and the P300 peak latencies were statistically of non-significant values between the study group and normal subjects. Discussion and Conclusion: Reduced waveform amplitudes were observed in IST than normal subjects. Possible mechanisms include that the processing of selective attention and its response to auditory tone burst stimuli associated with IST differ than that of the normal. The findings of our study are consistent with the hypothesis that IST patients differ in their response to auditory stimulus measured by P300 mainly auditory cortical area than normal subjects.