Cochlear implantation (CI) is a relatively new type of treatment that aims to re-establish hearing in deaf people. This paper reports on the results from CI operations on 34 adults and 17 children. All patients benefited from the treatment. The adults' communication with other people improved. Almost all patients use their implant 16 h a day and some of them are able to communicate by telephone. Among children the results show that the treatment is safe, as no complications have developed. Hearing and speech improved in all children, and thus also their ability to communicate. The results obtained are dependent on the individual patient's condition, the time of operation in relation to the development of deafness, and the type of CI used. CI treatment of deaf people may be considered to be one of the greatest advances in otology.