Luo Xin, Fu Qian-Jie
Department of Auditory Implants and Perception, House Ear Institute, 2100 West Third Street, Los Angeles, CA 90057, USA.
IEEE Trans Biomed Eng. 2005 Jul;52(7):1358-61. doi: 10.1109/TBME.2005.847530.
Because of the limited spectra-temporal resolution associated with cochlear implants, implant patients often have greater difficulty with multitalker speech recognition. The present study investigated whether multitalker speech recognition can be improved by applying speaker normalization techniques to cochlear implant speech processing. Multitalker Chinese vowel recognition was tested with normal-hearing Chinese-speaking subjects listening to a 4-channel cochlear implant simulation, with and without speaker normalization. For each subject, speaker normalization was referenced to the speaker that produced the best recognition performance under conditions without speaker normalization. To match the remaining speakers to this "optimal" output pattern, the overall frequency range of the analysis filter bank was adjusted for each speaker according to the ratio of the mean third formant frequency values between the specific speaker and the reference speaker. Results showed that speaker normalization provided a small but significant improvement in subjects' overall recognition performance. After speaker normalization, subjects' patterns of recognition performance across speakers changed, demonstrating the potential for speaker-dependent effects with the proposed normalization technique.
由于与人工耳蜗相关的频谱-时间分辨率有限，植入人工耳蜗的患者在多说话者语音识别方面往往有更大的困难。本研究调查了通过将说话者归一化技术应用于人工耳蜗语音处理，是否可以提高多说话者语音识别能力。使用正常听力的华语受试者，在有和没有说话者归一化的情况下，对四通道人工耳蜗模拟进行多说话者汉语元音识别测试。对于每个受试者，说话者归一化以在没有说话者归一化的条件下产生最佳识别性能的说话者为参考。为了使其余说话者与这种“最佳”输出模式匹配，根据特定说话者与参考说话者之间平均第三共振峰频率值的比率，为每个说话者调整分析滤波器组的整体频率范围。结果表明，说话者归一化在受试者的整体识别性能方面有小幅但显著的提高。经过说话者归一化后，受试者跨说话者的识别性能模式发生了变化，证明了所提出的归一化技术存在说话者依赖效应的可能性。
