Adult cochlear implant patient performance with evolving electrode technology

In 1998, clinical trials were initiated to evaluate the CLARION Multi-Strategy Cochlear Implant (Advanced Bionics Corp., Sylmar, CA, U.S.A.), a precurved electrode with an electrode positioning system (EPS) in adults with severe to profound hearing impairments. In 1999, clinical trials were initiated to assess the CLARION HiFocus electrode with EPS in a similar group of adults. The purpose of this retrospective study was to evaluate and compare the preoperative and 1-, 3-, and 6-month postoperative speech perception scores obtained by the first 56 patients implanted with the precurved electrode with EPS and the first 56 patients implanted with the HiFocus electrode with EPS. Speech strategy preferences were additionally noted and compared at each test interval for each group.

All subjects participated in preoperative testing with hearing aids and postoperative (1, 3 and 6 months) testing with either the precurved electrode with EPS or the HiFocus electrode with EPS. Demographic characteristics and preoperative and postoperative speech perception results were compared within and between the 2 groups.

Data presented here were collected at cochlear implant programs affiliated with tertiary medical centers located in the United States and Canada that participated in the clinical trials.

Patients were postlinguistically deafened adults who received a CLARION cochlear implant.

Within-group evaluations revealed that both groups demonstrated significant improvements on all speech perception measures when 1-month postoperative scores were compared with scores obtained preoperatively with hearing aids. Between-group comparison of demographic data showed that the HiFocus group had a significantly higher mean age at implant and a significantly longer mean duration of deafness than the precurved electrode with EPS group. Statistical comparison of mean speech perception scores showed no significant difference between subjects using the precurved electrode with EPS versus the HiFocus electrode with EPS at the preoperative, 1-, and 3-month test intervals. At the 6-month test interval, the mean CNC Monosyllabic Word Test score obtained by the HiFocus with EPS group was significantly better than the mean score obtained by the group with the precurved electrode with EPS (p < 0.05).