Judgments and measurements of the loudness of tinnitus before and after masking.

This study explored the relation between changes reported in the perception of the loudness of tinnitus after noise exposure and changes measured in matches to the loudness of tinnitus after noise exposure. Preexposure assessment of the loudness of tinnitus was followed by monaural exposure to wide-band Gaussian noise (for a 5-min period), after which a pulsed, 200-ms tone was presented either ipsilateral or contralateral to the exposed ear. Following each noise exposure, the subject (a) judged the change in the pre- and postexposure tinnitus strength and (b) compared the loudness of the postexposure tinnitus to that of the pure tone. By combining data across noise exposures, a measure of the postexposure tinnitus magnitude was computed. For three of six subjects, the pre- and postexposure magnitude did not differ significantly even though the judgments indicated that the pre- and postexposure loudness of the tinnitus had changed. These data raise the possibility that some loudness judgments reflect variability in the tinnitus rather than the effect of the noise on the tinnitus.