Prince Philip Dental Hospital, The University of Hong Kong, SAR, PR China.
J Speech Lang Hear Res. 2013 Aug;56(4):1166-74. doi: 10.1044/1092-4388(2012/12-0255).
This study examined the effects of envelope dynamic-range mismatch on the intelligibility of Mandarin speech in noise by simulated bilateral electric hearing.
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.
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.
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.
本研究通过模拟双侧电听觉，考察了在噪声环境中，包络动态范围不匹配对汉语语音可懂度的影响。
采用语音噪声对汉语语音进行噪声编码，信噪比分别为 5dB 和 0dB，分别向 10 名正常听力的受试者进行单侧或双侧识别。对于单侧条件，右耳接收到的是使用 15dB 包络动态范围（DR）生成的 8 通道噪声编码刺激。为了模拟双耳之间的包络 DR 不匹配，左耳分别接收到使用 5dB、10dB 或 15dB 包络 DR 生成的 8 通道噪声编码刺激。
仅当双耳的包络 DR 匹配时，才观察到汉语语音识别的显著双耳总和增益。随着 DR 的降低，在稳态语音噪声中，音调识别的性能比句子识别更一致。
与先前的发现一致，本研究结果表明，双侧电听力在噪声中对汉语语音感知的表现受到双耳植入体之间包络 DR 差异的影响，当双耳植入体之间的 DR 不匹配减小时，双耳总和增益最大化。
