gms | German Medical Science

Purpose: This study aimed to evaluate Chinese speech recognition performance processed by a hearing aid (HA) that is additive to information processed by a cochlear implant (CI) in noise and quiet.

Method: Vowel, consonant, and tone recognition was measured in CI alone and combined CI and HA condition. Thirteen Mandarin-speaking CI patients (7 male and 6 female, aged 16 to 24 years old) participated in this study. All CI subjects had more than six months of experience with their device at the time of testing. Speech recognition was measured in both quiet and in 5 dB signal-to-noise ratio (six-talker babble noise).

Results: Results showed a clear bimodal benefit (performance with CI+HA minus that with CI alone) for vowel (11.5%), consonant (7.4%), and tone recognition (6.2%) in quiet. Similar bimodal benefit was observed in noise for both vowel (9.2%) and tone recognition (9.7%) while no bimodal benefit was observed for consonant recognition. There was significant correlation between bimodal benefits and aided pure-tone average for consonant recognition in quiet and in noise, and for vowel recognition in quiet. Significant correlation between bimodal benefits and duration of bimodal use for tone recognition in quiet was also observed.

Conclusions: The bimodal listening provides significant benefit in quiet and in noise for Chinese tone and vowel recognition. The bimodal advantage in Chinese vowel and consonant recognition is dependent on the aided pure tone average. The bimodal advantage in Chinese tone recognition is dependent on the duration of bimodal use, indicating that CI users need to learn how to combine the F0 cues from acoustic hearing and amplitude cues from electric hearing for tone perception.