[Cochlear implant--possibilities and limitations]

Provided that the auditory nerve is fully preserved and that the hearing impairment has not persisted for more than a few years, the cochlear implant offers a satisfactory, though not perfect, replacement for the defunct inner ear. Unfortunately, prior to operation, the residual function of the auditory nerve in patients with labyrinthine deafness cannot be determined quantitatively, but can merely be noted to be present or not. As the duration of the impairment lengthens, we must expect progressive degeneration of auditory nerve fibers, and increasing deprivation of the central auditory pathways. The limitations of cochlear implants are thus determined by an impairment that has persisted for decades, as also early-prelingual-development of the impairment. This also means that adults who were born deaf should not be recommended for the procedure. This should stimulate us all the more to create the conditions to ensure that the young deaf child can benefit from cochlear implantation at as early an age as possible. At the present time, we are attempting to work out surgical techniques and rehabilitative measures for cochlear implants in young deaf children.