Extracochlear sixteen-channel electrode system.

This article summarizes 10 years of work by the Cologne-Düren Research Group. The purpose of our research was to develop a noninvasive operation technique and to avoid opening the inner ear cavities (extracochlear technique). On the basis of empiric experience, a 16-channel electrode system was developed. The electrodes were fixed on a "hedgehog" contact plate with an arrangement corresponding to the projection of the cochlea. A microprocessor, which enables individual programmability in the different groups of deaf persons (prelingual, postlingual deafness), was integrated into the speech processor. Experience to date was summarized in statistical data. Not only the results of the psychoacoustic tests, but also the applicability of the cochlear implant as seen by the patients were considered. We next plan to miniaturize the system.