Matching of Tinnitus Frequency in Patients with Normal Hearing and with Hearing Loss

Background: Subjective tinnitus often occurs in association with peripheral hearing loss, but can also be present in normal hearing subjects.

Objective: To explore the differences in tinnitus characteristics in patients with hearing loss and in normal hearing.

Methods: 17 patients (7 males, 10 females; mean age 46±11.9 years) with tinnitus symptoms were enrolled in the study. All participants complained on subjective non-pulsatile constant tinnitus for at least three months duration. Pure-tone thresholds were measured at all standard frequencies from 0.25 to 8 kHz, and at 10, 12.5, 14, 16 and 20 kHz. Tinnitus symptoms were assessed with Tinnitus Handicap Inventory (THI). Of all patients, 7 had normal hearing (Group 1) and 10 patients had high frequency hearing loss (Group 2). For tinnitus pitch matching was used stimuli in the contralateral ear. Matched frequency tinnitus pitches were compared in both groups. Masking therapy was applied to all patients. Its effectiveness was evaluated with THI.

Results: The THI showed significant similar results between two groups before therapy. In Group 1 we failed to match pitch frequency of tinnitus in 6 patients and in 1 patient the tinnitus frequency was app. 14 kHz. The applied masking therapy was not effective in all patients of Group 1. In Group 2 all patients were diagnosed the tinnitus frequency in the range of maximum hearing loss (2-14 kHz) and loudness of tinnitus was +5-7 dB above the hearing loss. In 7 patients (70%) in Group 2 masking therapy was effective.

Conclusion: In normal hearing patients with tinnitus it was not possible to detect the tinnitus pitch in majority of cases, which obviously caused the failure of masking therapy. In patients with tinnitus and hearing loss the tinnitus frequency was detected in the range of maximum hearing loss and the masking therapy was effective.