A comparison of variability among measurements of subjective tinnitus and objective stimuli.

8 patients with subjective tinnitus were trained in pitch-matching, loudness-matching, and simultaneous-masking tasks using narrow-band noise and/or pure-tone stimuli. Extensive pitch-matching, loudness-matching and masking measurements were then obtained for their tinnitus, after which the same measurements were obtained for objective stimuli which approximated the frequency and intensity of the tinnitus. Variability for pitch and loudness matching to tinnitus was extremely large relative to the same measurements for objective stimuli. This was particularly true for pitch-matching where even the most consistent patients showed variability for matches to their tinnitus which was an order of magnitude greater than for matches to objective stimuli in the same frequency region. No evidence of frequency-specific masking of tinnitus was seen in any of the patients although such evidence was obtained for the masking of objective stimuli. The results suggest that the large variability in matches to tinnitus, and the lack of normal frequency-specific masking of tinnitus in these patients may reflect interactions at levels higher than the end-organ rather than a degradation in peripheral auditory function.