CLARION COCHLEAR IMPLANT - TECHNICAL BACK GROUND, INITIAL CLINICAL-EXPERIENCE AND RESULTS

Background: Certain design characteristics of the Clarion device (Adva nced Bionics Corp.) make it significantly different from other cochlea r implant systems. It has a preformed electrode array to be placed clo ser to the modiolus. thus providing a more efficient coupling of the e lectrical signal to the auditory nerve; a telemetric function which pe rmits the evaluation of the implant electronics: and two different spe ech processing strategies. The strategies are continuous interleaved s ampling (CIS) and compressed analog (CA); both can be programmed into the same speech processor and alternatively selected by the patients, as they desire. The surgical procedure is only slightly different from the procedure familiar from the Nucleus system with the exception of a significantly larger cochleostomy. Patients: The results of a series of speech tests designed to evaluate benefit in terms of speech under standing were administered to the first ten Clarion patients and compa red to the results of a similar group of patients using the Nucleus sy stem and the M Peak method. From a database of more than 300 Nucleus u sers, it was possible to select ten subjects who had near-equivalent d ata for onset of deafness, duration of deafness, and age at implantati on (so-called matched pairs). In the majority of cases, etiology and c ourse of deafness (progressive or sudden) could also be matched. Resul ts: It was found that the Clarion patients had higher test scores than the Nucleus patients after two weeks, three months, and six months af ter implantation. This positive experience with the Clarion device enc ouraged us to continue implanting this system in patients. As of Septe mber 1995, 106 patients (including 35 children between the ages of two and fourteen) are currently enrolled in the study. Conclusions: A fin al assessment of results with the Clarion implant is not possible beca use of the short follow-up. In any case, it appears that the patients with this implant system achieve faster open-set speech understanding and that it is accomplished with less effort in programming and shorte r rehabilitation time.