Tonal Tinnitus Does Not Interfere with Tone Detection at the Tinnitus Pitch-Matched Frequency

Individuals with tinnitus hear sounds that are not present in the external environment. Whereas hearing difficulties at frequencies near those matching the tinnitus pitch are a common complaint for individuals with tinnitus, it is unclear to what extent the internal tinnitus sounds interfere with the detection of external sounds. We therefore studied whether pure-tone detection at the estimated frequency corresponding to the tinnitus pitch (f_tp) was affected by confusion with the tinnitus percept. Signs of confusion would be a high false alarm rate or a shallower slope of the psychometric function for tone detection at f_tp. We selected participants with symmetric, tonal tinnitus, who were able to estimate its pitch consistently (n = 18). Another 18 participants matched for high-frequency hearing loss, age, and sex, but without tinnitus, served as the control group. For both groups, we measured the psychometric function for detecting long-duration tones, maximizing the likelihood for confusion with an external sound. We observed that false alarm rates for tinnitus participants were not higher for test tones at f_tp, nor were they higher than for the control group without tinnitus. Similar results were obtained for the slopes of the psychometric functions. Apparently, individuals with tinnitus are well able to discriminate between their own tinnitus and comparable external sounds. Our results indicate that (tonal) tinnitus does not interfere with the detection of soft sounds at the tinnitus pitch-matched frequency.