Optimizing Rehabilitation in Single-Sided Deafness: Restoration of binaural hearing by cochlear implantation

Part I is an introduction on the rehabilitation of single-sided deafness (SSD). In the first literature review, the current treatment options for SSD are discussed: bone conduction devices (BCD) and contralateral routing of sound hearing aids (CROS). The second review focuses on cochlear implantation (CI) for SSD. There were no high level of evidence studies comparing BCD, CROS and CI for patients with SSD. Based on available literature, cochlear implantation seemed to be a promising treatment option.

Part II describes the study protocol and short-term results of a randomized controlled trial investigating the treatment options for adult SSD patients. Speech perception in noise improved in all configurations for the CI group. For the speech the BCD and CROS groups, speech perception in noise improved when speech was presented to the poor ear, but deteriorated when speech was presented to the better ear. Only in the CI group, sound localization improved and tinnitus burden/distress decreased. In general, all treatment options improved disease-specific QoL on most subscales of the used questionnaires

Part III details additional experiments that were performed in SSD patients implanted with a CI. They have the unique ability to compare sounds of their cochlear implant to sounds presented to their contralateral normal-hearing ear.

In Part IV, we found that both the reporting of systematic reviews and of RCTs in otorhinolaryngologic journals leaves room for improvement.

Finally, in Part V, the findings of the previous chapters are summarized and discussed, and future directions for research are provided.