Speech intelligibility in cochlear implant simulations: Effects of carrier type, interfering noise, and subject experience
Speech intelligibility in cochlear implant simulations: Effects of carrier type, interfering noise, and subject experience
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DOI：
10.1121/1.2773993
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发表时间：
2007-10-01
影响因子：
2.4
通讯作者：
Helfer, Karen S.
中科院分区：
文献类型：
--
作者：
Whitmal, Nathaniel A., III;Poissant, Sarah F.;Helfer, Karen S.
使用音调或带限噪声载波的信道声码器已在实验中用于模拟听力正常的听众中的耳蜗植入处理。这些实验的先前结果表明，这两种声码器类型在安静条件下产生几乎相等的可懂度的语音。本研究的目的是进一步比较在安静和嘈杂的听音条件下的音调和噪声带声码器的性能。在四个实验中，听力正常的受试者能够更好地识别音调语音编码的句子和元音-辅音-元音音节比噪声语音编码的句子和音节，无论是在安静的和存在的语音频谱噪声或两个谈话者的牙牙学语。在安静和语音频谱噪声中对辅音混淆进行的分析揭示了显着不同的错误模式，这些错误模式与每个声码器产生音调或噪声输出的能力有关，这些输出准确地反映了辅音的发音方式。受试者的经验也被证明会影响可懂度。使用调制检测的计算模型的仿真表明，噪声声码器的缺点部分是由于其载波的固有时间波动，这可能会干扰传达语音识别线索的时间波动。(C)2007年，美国声学学会。
Channel vocoders using either tone or band-limited noise carriers have been used in experiments to simulate cochlear implant processing in normal-hearing listeners. Previous results from these experiments have suggested that the two vocoder types produce speech of nearly equal intelligibility in quiet conditions. The purpose of this study was to further compare the performance of tone and noise-band vocoders in both quiet and noisy listening conditions. In each of four experiments, normal-hearing subjects were better able to identify tone-vocoded sentences and vowel-consonant-vowel syllables than noise-vocoded sentences and syllables, both in quiet and in the presence of either speech-spectrum noise or two-talker babble. An analysis of consonant confusions for listening in both quiet and speech-spectrum noise revealed significantly different error patterns that were related to each vocoder's ability to produce tone or noise output that accurately reflected the consonant's manner of articulation. Subject experience was also shown to influence intelligibility. Simulations using a computational model of modulation detection suggest that the noise vocoder's disadvantage is in part due to the intrinsic temporal fluctuations of its carriers, which can interfere with temporal fluctuations that convey speech recognition cues. (C) 2007 Acoustical Society of America.