Review of the roles of temporal and place coding of frequency in speech discrimination
Review of the roles of temporal and place coding of frequency in speech discrimination
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DOI：
10.1080/00016489950180946
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发表时间：
1999-01-01
影响因子：
1.4
通讯作者：
Moller, AR
中科院分区：
文献类型：
--
作者：
Moller, AR
许多研究表明，声音的频谱在空间和时间上都表现在单个听觉神经纤维的神经编码中，但很少有人设计实验来测试这两种频率表示中哪一种用于识别复杂的声音，如语音和音乐。本文综述了频率的位置编码和时间编码在神经系统中作为识别语音等复杂声音频率的基础所起的作用。基于耳蜗频率分析的动物研究表明，位置编码作为声强的函数系统地变化，因此缺乏解释音高感知所需的鲁棒性（人类），这几乎与声强无关。位置原则在言语辨别中起次要作用的进一步迹象来自于一些个体耳蜗频谱分析障碍的迹象与言语辨别障碍无关的观察。时间编码的重要性得到了观察结果的支持，即听觉神经损伤被认为损害了听觉神经纤维放电的时间一致性，与言语识别的严重障碍有关。这些观察结果表明，语音的时间编码比位置编码对语音的辨别更重要。讨论了这些发现对人工耳蜗等植入物设计的意义。
Numerous studies have demonstrated that the frequency spectrum of sounds is represented in the neural code of single auditory nerve fibres both spatially and temporally, but few experiments have been designed to test which of these two representations of frequency is used in the discrimination of complex sounds such as speech and music. This paper reviews the roles of place and temporal coding of frequency in the nervous system as a basis for Frequency discrimination of complex sounds such as those in speech. Animal studies based on frequency analysis in the cochlea have shown that the place code changes systematically as a function of sound intensity and therefore lacks the robustness required to explain pitch perception tin humans), which is nearly independent of sound intensity. Further indication that the place principle plays a minor role in discrimination of speech comes from observations that signs of impairment of the spectral analysis in the cochlea in some individuals are not associated with impairments in speech discrimination. The importance of temporal coding is supported by the observation that injuries to the auditory nerve, assumed to impair temporal coherence of the discharges of auditory nerve fibres, are associated with grave impairments in speech discrimination. These observations indicate that temporal coding of sounds is more important for discrimination of speech than place coding. The implications of these findings for the design of prostheses such as cochlear implants are discussed.