Cochlear implantation on prelingually deafened adults.

OBJECTIVE To evaluate the validity of cochlear implantation (CI) on prelingually deafened adults who have been trained by auditory-verbal/oral communication since childhood. METHODS Preoperative and postoperative data was investigated regarding the rehabilitation, hearing level, and educational experience of eight prelingually deafened adults. All eight patients were diagnosed with severe to profound sensorineural hearing loss (preoperative hearing levels were over 100 dB). All used hearing aids (HA) before the age of two and were trained by auditory-verbal/oral communication since childhood. The average age of the patients at the time of their CI operations was 23.3 ranging from 18 to 29 years of age. The average postoperative observation time was 55.4 months ranging from 11 to 90 months. RESULTS Improvement was achieved not only on the pure-tone hearing threshold, but also in speech perception on tests using the Japanese video speech discrimination score (SDS) system. All of them now use CI very well in their daily lives and play important roles in society. CONCLUSION It was demonstrated that even prelingually deafened adult patients could achieve considerable improvement through CI when they were trained well by auditory-verbal/oral communications since childhood. The indications of CI for prelingually deafened adults must be determined carefully, but all of them do not have to be rejected only because they are prelingually deafened. In other words, CI could be recommended for prelingually deafened adult patients if they received habilitation well with consistent auditory-verbal/oral training using well-fitted HAs.