A reexamination of the long latency N1 response in patients with tinnitus.

There have been disparate findings reported previously by investigators who have examined differences in the cortically generated N1 (i.e., N100) from control and tinnitus samples. Investigators have employed differing stimulation paradigms applied to relatively small subject samples. Accordingly, it is not surprising that there has been no unanimity in the reported findings. The present investigation was conducted to determine, once again, whether differences exist in the cortically generated N1 potential recorded from both normals and subjects with bothersome tinnitus. In this investigation both passive and selective auditory attention paradigms were employed. Subjects were a total of 63 adults (31 controls and 32 tinnitus patients). The mean score on the Tinnitus Handicap Inventory for the tinnitus group was 39 points. Results failed to reveal group differences in the latency of N1 across listening conditions. However, tinnitus patients demonstrated N1 potentials that were of significantly smaller amplitude than those obtained from normal subjects. These findings are consistent with those reported in previous investigations.