[Multichannel cochlear implant: personal experience].

Cochlear Implantation is a recognized procedure for acoustical rehabilitation of the profoundly or totally deaf unable to effectively use a traditional hearing aid. Since 1989, 30 patients (27 postlingual and 3 perilingual) have been operated on by the senior Author with the implantation of a multichannel device: Med-El (3 cases), Clarion (3 case) and Nucleus Mini-22 (24 cases). The first 24 Nucleus cases, with a multipeak speechcoding strategy, are the object of this retrospective report. Selection of patients was performed according to an international protocol which includes PTA and Speech Audiometry, CT and/or MRI imaging of the ear, the Promontorial Test, an evaluation of lip reading ability, a psychological evaluation, a trial with two recent and currently available aids. The operation was carried out under general anesthesia. An extended endaural approach was adopted. The internal package of the device was firmly seated onto the temporalis squama and the electrode array was introduced into the tympanic cleft via a posterior tympanotomy. The electrode system was inserted into the scala tympani through a cochleotomy drilled out at the anteroinferior border of the round window. The whole system was fixed to the bony walls of the mastoid and squama using an ionomeric bone bonding agent. Starting at the second postoperative month and up to the 24th month of utilization of the device, each patient was evaluated with regard to his or her ability to recognize environmental sounds, to detect prosody transitions and to understand speech with and without visual cues. Selected tests, either close or open set, were used from the MAC and the Iowa Cochlear Implant Battery, as well as the Helen test. Telephone conversation was also evaluated. Results were very encouraging in all cases, showing that the multichannel cochlear device provides the properly selected patient a substantial auditory rehabilitation allowing him or her to understand speech in most instances without any visual cue.