The effect of cochlear implant and bimodal stimulation on tinnitus: a multinational survey.

Background: Tinnitus is a frequent symptom in cochlear implant (CI) patients. Many studies have shown that a CI leads to a significant change in the perception of tinnitus.

Aims: The aim of the present study was to evaluate the effect of CI on tinnitus in patients with Unilateral Cochlear Implant (UCI), Bilateral Cochlear Implant (BCI), and Bimodal Stimulation (BMS).

Material and methods: A survey was administered online to CI patients. The Tinnitus Handicap Inventory (THI) score was calculated. Emotional, functional, and catastrophic subscales scores were calculated. The intensity and annoyance of tinnitus were graded using a scale from 1 to 10.

Results: 130 participants represented the study group; the Average THI score was 38.3 (SD: 26.3) in UCI, 32.4 (SD 25.8) in BCI users, and 42.5 (SD 28.2) in BMS: no significant difference was found among the three groups. CI users for less than 1 year showed significantly higher THI scores compared to CI users for more than 5 years (p = .0275). The intensity and annoyance of tinnitus significantly decreased with the CI on compared to the CI off condition.

Conclusions and significance: Taken together, our findings support CI's efficacy in reducing the perception of tinnitus. No significant differences were evident between unilateral and bilateral electrical stimulation in terms of tinnitus improvement.