Bimodal Hearing Benefit for Speech Recognition with Competing Voice in Cochlear Implant Subject with Normal Hearing in Contralateral Ear

Objectives: This project assessed electroacoustic benefit for speech recognition with a competing talker. Design: Using a cochlear implant subject with normal hearing in the contralateral ear, the contribution of low-pass and high-pass natural sound to speech recognition was systematically measured. Results: High-frequency sound did not improve performance, but low-frequency sound did, even when unintelligible and limited to frequencies below 150 Hz. Conclusions: The low-frequency sound assists separation of the two talkers, presumably using the fundamental frequency cue. Extrapolating this finding to regular cochlear implant users may suggest that using a hearing aid on the contralateral ear will improve performance, even with limited residual hearing.