Acoustic plus electric speech processing: preliminary results of a multicenter clinical trial of the Iowa/Nucleus Hybrid implant.

AIM: This communication details the latest preliminary results from an ongoing multicenter single-subject design clinical trial of the Iowa/Nucleus Hybrid 10-mm cochlear implant. Selection criteria, surgical strategies used for hearing preservation, and the benefits of preserved residual low-frequency hearing, improved word understanding in noise, and music appreciation are described.

PATIENTS AND METHODS: The device has been implanted in 48 individuals with residual low-frequency hearing.

RESULTS: Hearing preservation has been accomplished in 46/48 subjects. Acoustic speech perception has also been preserved. Combined acoustic plus electric speech processing has enabled most of this group of volunteers to gain improved word understanding as compared to their preoperative hearing with bilateral hearing aids. A subset of subjects with 12 months or more experience demonstrates CNC word understanding continues to improve more than 24 months after implantation. Improved word understanding in noise is also a benefit of acoustic plus electric speech processing.

CONCLUSIONS: The improvement of speech in noise and melody recognition is linked to the ability to distinguish fine pitch differences as the result of preserved residual low-frequency acoustic hearing. Both of these measures are very important in real life to the hearing impaired. Preservation of residual low-frequency hearing should be considered when expanding candidate selection criteria for standard cochlear implants.