Objective: Cochlear implantation is the current standard of care in patients with significant sensorineural hearing loss. The purpose of this study was to assess the effects of cochlear implantation on ipsilateral tinnitus.
Methods: With standard assessment table and standard testing program, 48 postlingual hearing-impaired adults aged 18 - 62 years (mean age at implantation: 35.0) were operated at 5 clinical centers from June 2009 to March 2010. There were 23 males (47.9%) and 25 females (52.1%). We evaluated the pre- and post-implantation degrees of tinnitus, performed free sound field audiometry and scored speech perception during different periods. Secondary analyses were conducted to examine the correlation between the effects of implantation on tinnitus and hearing or speech perception rehabilitation.
Results: Before implantation, there were 16 cases with ipsilateral tinnitus and 32 cases without tinnitus. After implantation, among 16 cases, the outcomes were recovery (n = 6), tinnitus suppression (n = 1) and no change in symptoms (n = 9). The total effective rate was 43.8%. Among another 32 cases without preoperative tinnitus, 2 cases developed tinnitus after implantation. The effects of cochlear implantation on tinnitus were negatively correlated with the course of tinnitus. There was no more correlation with other factors.
Conclusion: Cochlear implants have significant therapeutic effects on tinnitus in 43.8% of implant users. Better efficacies are correlated with a shorter course of tinnitus. However, tinnitus suppression using electrical stimulation via cochlear implantation for deafness needs to be further evaluated.