The cognitive profile of older adults with a severe to profound hearing impairment is determined by means of the Repeatable Battery for the Assessment of Neuropsychological Status, adjusted for Hearing impaired subjects (RBANS-H) before and after cochlear implantation. In this prospective, longitudinal study the participants are tested preoperatively, at six months and twelve months postoperatively and from then on yearly up to 10 years after implantation. In addition to the RBANS-H an audiological examination and an semistructured interview is conducted concerning the cochlear implant use and the self-reliance of the patient and subjective questionnaires are filled out by the subjects to assess quality of life and hearing benefit.