【摘要】 各种时域包络信息中,周期波动信息能显著增强频谱信息严重受损时的中文音调和句子识别;分析各频段的时域周期波动信息对中文语音识别的作用具有重要的理论和实际意义。为了在不同频段中保留时域周期波动信息,4频段电子耳蜗声学模拟实验使用不同的低通滤波截止频率来提取各频段的时域包络。6种低通滤波截止频率组合包括:4频段都使用50Hz(all-50),4频段都使用500Hz(all-500),4频段中某一频段使用500Hz而其余三频段使用50Hz(ch1-500等)。辨识结果显示:ch4-500组合产生最高的,与all-500组合相似、比all-50组合显著增强的音调识别;而元音识别则不随低通滤波截止频率组合发生显著变化。这表明传递最高频段的时域周期波动信息对增强电子耳蜗使用者的中文音调识别最重要。更多还原

【Abstract】 Studies have revealed near perfect speech recognition with primarily temporal envelope cues and severely degraded spectral cues.Among different types of temporal envelope cues,periodicity fluctuation cues have been found to significantly improve Chinese tone and sentence recognition,while the contributions of periodicity fluctuation cues in individual frequency channels to Chinese speech recognition have not been clearly stated.In order to make periodicity fluctuation cues available in different frequency regions,the present study employed different lowpass cutoff frequencies for the temporal envelope detectors in different channels of a fourchannel noiseband cochlear implant simulation.Chinese tone and vowel recognition scores were measured for six native Chinese normal hearing listeners under six lowpass cutoff frequency combinations: all 50 Hz in four channels(all50),all 500 Hz in four channels(all500),and 500 Hz in one of the four channels while 50 Hz in the other three channels(ch1500,ch2500,et al.).The results showed that the ch4500 condition produced the highest Chinese tone recognition among the four singlechannel500 Hz conditions,and was the only condition whose tone recognition was similar to that of the all500 condition and significantly higher than that of the all50 condition.Chinese vowel recognition was not significantly affected by different cutoff frequency combinations.These results suggest that delivering periodicity fluctuation cues inhigher frequency channels may be more important and efficient in enhancing Chinese tone recognition for cochlear implant patients.更多还原