The contribution of matched envelope dynamic range to the binaural benefits in simulated bilateral electric hearing.
OBJECTIVE
This study examined the effects of envelope dynamic-range mismatch on the intelligibility of Mandarin speech in noise by simulated bilateral electric hearing.


METHODS
Noise-vocoded Mandarin speech, corrupted by speech-shaped noise at 5 and 0 dB signal-to-noise ratios, was presented unilaterally or bilaterally to 10 normal-hearing listeners for recognition. For unilateral conditions, the right ear was presented with the 8-channel noise-vocoded stimuli generated using a 15-dB envelope dynamic range (DR). To simulate the envelope DR mismatch between the 2 ears, the left ear was presented with the 8-channel noise-vocoded stimuli generated using a 5-, 10-, or 15-dB envelope DR, respectively.


RESULTS
Significant binaural summation benefits for Mandarin speech recognition were observed only with matched envelope DR between the 2 ears. With reduced DR, the performance of tone identification was more consistent in the steady-state speech-shaped noise than that of sentence recognition.


CONCLUSIONS
Consistent with previous findings, the present results suggest that Mandarin speech-perception performance of bilateral electric listening in noise is affected by the difference of envelope DR between the 2 implanted ears, and the binaural summation benefits are maximized when DR mismatch is minimized between the 2 implanted ears.
Prince Philip Dental Hospital, The University of Hong Kong, SAR, PR China. feichen1@hku.hk
Fei
F
Chen
Lena L N
LL
Wong
Jianxin
J
Qiu
Yehai
Y
Liu
Behnam
B
Azimi
Yi
Y
Hu
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000328:Adult; D044466:Asian People; D019929:Cochlear Implantation; D003054:Cochlear Implants; D004007:Dichotic Listening Tests; D005260:Female; D006801:Humans; D008297:Male; D009622:Noise; D010700:Phonetics; D021641:Recognition, Psychology; D059629:Signal-To-Noise Ratio; D013063:Speech Discrimination Tests; D013067:Speech Perception; D055815:Young Adult
bilateral electric hearing; binaural benefits; dynamic range; electric hearing