Enhancement of temporal periodicity cues in cochlear implants: Effects on prosodic perception and vowel identification
Enhancement of temporal periodicity cues in cochlear implants: Effects on prosodic perception and vowel identification
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DOI：
10.1121/1.1925827
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发表时间：
2005-07-01
影响因子：
2.4
通讯作者：
Macherey, O
中科院分区：
文献类型：
--
作者：
Green, T;Faulkner, A;Macherey, O
标准的连续交错采样处理，和修改后的处理策略，旨在提高语音音高的时间线索，进行了比较的语调感知测试，元音感知，无论是在植入用户和声学模拟。在标准处理中，400 Hz低通包络调制脉冲串（植入用户）或噪声载波（模拟）。在修改后的策略，慢速率包络调制，传达动态频谱变化的语音理解至关重要，通过低通滤波（32 Hz）提取。此外，在有声语音期间，每个通道中的更高速率的时间调制由锯齿状波形的100%幅度调制提供，锯齿状波形的周期性遵循输入的基频（FO）。信道电平由较低速率调制分量和较高速率调制分量的乘积确定。在声学模拟和植入用户中，使用语调信息将句子识别为问题或陈述的能力在修改后的处理中明显更好。然而，虽然在声学模拟中元音识别没有差异，但植入用户在元音识别和共振峰频率辨别方面的修改处理表现更差。看来，虽然提高音高知觉，修改处理损害了频谱信息的传输。(c)2005年美国声学学会。
Standard continuous interleaved sampling processing, and a modified processing strategy designed to enhance temporal cues to voice pitch, were compared on tests of intonation perception, and vowel perception, both in implant users and in acoustic simulations. In standard processing, 400 Hz low-pass envelopes modulated either pulse trains (implant users) or noise carriers (simulations). In the modified strategy, slow-rate envelope modulations, which convey dynamic spectral variation crucial for speech understanding, were extracted by low-pass filtering (32 Hz). In addition, during voiced speech, higher-rate temporal modulation in each channel was provided by 100% amplitude-modulation by a sawtooth-like wave form whose periodicity followed the fundamental frequency (FO) of the input. Channel levels were determined by the product of the lower- and higher-rate modulation components. Both in acoustic simulations and in implant users, the ability to use intonation information to identify sentences as question or statement was significantly better with modified processing. However, while there was no difference in vowel recognition in the acoustic simulation, implant users performed worse with modified processing both in vowel recognition and in formant frequency discrimination. It appears that, while enhancing pitch perception, modified processing harmed the transmission of spectral information. (c) 2005 Acoustical Society of America.