Does tinnitus affect the sound localization ability?

摘要

Objective: To investigate whether tinnitus affects sound localization ability. Study Design: Prospective controlled study. Setting: Tertiary referral center. Patients: Forty tinnitus patients (mean age, 36.7 ± 14.3 yr; hearing threshold, <20 dB HL; tinnitus group) and 40 controls (mean age, 39.3 ± 12.9 yr; hearing threshold, <20 dB HL; control group). Methods: We performed a sound localization test (SLT) with 7 speakers positioned in a semicircle on the horizontal plane at a distance of 1 m from the subject, at 30-degree intervals. Subjects were asked to identify the stimulus-presenting speaker, through a forced-choice procedure. The error score was calculated by scoring 1 point for each 30 degrees of difference between the stimulus-presenting speaker and the speaker identified by the subject. Results: The mean SLT total error score (TES) of the tinnitus group (18.8 ± 9.2) was significantly higher than that of the control group (13.1 ± 7.5) (p < 0.05). Regarding SLT responses for stimulation from speakers located at each side of the listener, mean TES in patients with tinnitus on the same side as the speaker was higher than that in patients with opposite side or bilateral tinnitus. Age showed a positive correlation with TES in the tinnitus (r = 0.44, p < 0.05) and control groups (r = 0.35, p < 0.05). Conclusion: We consider that tinnitus interferes with sound localization ability and that interference is worse for sound originating from the same side as the tinnitus. Age is a worsening factor in sound localization ability.