Cochlear implant treatment of patients with single-sided deafness or asymmetric hearing loss

The rehabilitation of patients with single-sided deafness (SSD) or asymmetric hearing loss can be achieved with conventional (Bi)CROS hearing aids ((Bi)CROS-HA, (Bi)CROS), bone conduction devices (BCI) or with cochlear implants (CI). Unfortunately, only small case series have been published on the treatment outcomes in SSD patients after CI surgery and there are only a few comparative studies evaluating rehabilitation outcomes. The aim of this study was to provide evidence of successful treatment of SSD and asymmetric hearing loss with a CI compared to the untreated, monaural hearing condition and the therapy options of BCI and (Bi)CROS in a large number of patients. In a single-centre study, 45 patients with SSD and 40 patients with asymmetric hearing loss were treated with a CI after careful evaluation for CI candidacy. Monaural speech comprehension in noise and localisation ability were examined with (Bi)CROS-HA and BCI devices (on a test rod) both preoperatively and at 12 months after CI switch-on. At the same intervals, subjective evaluation of hearing ability was conducted using the Speech, Spatial and Qualities of Hearing Scale (SSQ). This report presents the first evidence of successful binaural rehabilitation with CI in a relatively large patient cohort and the advantages over (Bi)CROS and BCI in smaller subgroups, thus confirming the indication for CI treatment. Moreover, patients with long-term acquired deafness (> 10 years) show a benefit from the CI comparable to that observed in patients with shorter-term deafness.