Tinnitus with normal hearing sensitivity: extended high-frequency audiometry and auditory-nerve brain-stem-evoked responses.

Extended high-frequency (HF) audiometry and auditory-nerve brain-stem-evoked responses (ABR) were carried out on two groups of subjects with normal hearing sensitivity. The experimental group comprised 17 subjects with tinnitus, while the control group consisted of age- and sex-matched subjects, not suffering from tinnitus. The aim of the study was to determine whether extended HF audiometry or ABR might reveal significant differences between these two groups of subjects with normal hearing sensitivity. In addition, the characteristics of tinnitus in subjects with normal audiograms were discussed. The results of extended HF audiometry showed no significant differences between the subjects with and without tinnitus. The ABR parameters considered were also within normal limits bilaterally. Based on the methods employed in this study, tinnitus in normal listeners does not appear to reflect appreciable damage in the cochlea or in the brain-stem auditory pathways. The authors present some suggestions for future research.