Cochlear implantation systems’ setting up features in partial hearing loss

Egorov Alexey I., Glukhovskiy Evgeniy M.

Electroacoustic stimulation is a popular therapy for people with hearing loss. These patients have not use hearing aids as traditionally because of strong residual hearing. The authors have presented the possibilities to preserve the remaining low-frequency hearing in these individuals and to provide a significant improvement in the quality of life by combining a cochlear implant with a hearing aid to amplify sound in the damaged ear. These modifications are especially noticeable when testing noise and speech recognition and identification. It is often overlooked these results can be influenced by the settings of both the cochlear implant and the hearing aid. Four subjects were assessed in this study using EAS for at least 1 month to eight different fitting parameters and at various noise levels in particular. Subjects also rated each condition using a visual analog scale. The results have shown reducing cochlear implant overlap and hearing aid reinforcement gives the best results in all testing conditions. So, the study results made it possible to concluded that the hearing aid should correspond to the modified audiogram of a particular patient, at least until the moment low-frequency hearing would be analyzed. The cochlear implant should be inserted at a higher frequency than the standard implantation system (for patients without residual hearing in the implanted ear). This is necessary to provide less frequency overlap with the gain provided by the hearing aid. Therefore, a small overlap between the frequency bands used by the hearing aid and the cochlear implant is the most effective.

Keywords:electroacoustic stimulation, hearing loss, cochlear implant, audiogram, noise level.