[Status of the development of cochlear prostheses relying on electric stimulation]

Inner ear prostheses, or cochlear implants, are neuroprostheses providing profoundly deaf people with sound sensations through electrical stimulation of the auditory nerve. Approximately 2,000 of these devices are currently in use worldwide. Five models are each being used by more than 50 patients. Among other features they differ from one another mainly in the design and placement of electrodes and in the particular speech coding strategy used, periodicity and tonotopy priciple being made use of to a highly varying degree. Nevertheless, 4 of the 5 devices lead to quite comparable degrees of speech understanding without additional lipreading.