Green K P, Tomiak G R, Kuhl P K
Psychology Department, University of Arizona, Tucson 85721, USA.
Percept Psychophys. 1997 Jul;59(5):675-92. doi: 10.3758/bf03206015.
The acoustic structure of the speech signal is extremely variable due to a variety of contextual factors, including talker characteristics and speaking rate. To account for the listener's ability to adjust to this variability, speech researchers have posited the existence of talker and rate normalization processes. The current study examined how the perceptual system encoded information about talker and speaking rate during phonetic perception. Experiments 1-3 examined this question, using a speeded classification paradigm developed by Garner (1974). The results of these experiments indicated that decisions about phonemic identity were affected by both talker and rate information: irrelevant variation in either dimension interfered with phonemic classification. While rate classification was also affected by phoneme variation, talker classification was not. Experiment 4 examined the impact of talker and rate variation on the voicing boundary under different blocking conditions. The results indicated that talker characteristics influenced the voicing boundary when talker variation occurred within a block of trials only under certain conditions. Rate variation, however, influenced the voicing boundary regardless of whether or not there was rate variation within a block of trials. The findings from these experiments indicate that phoneme and the rate information are encoded in an integral manner during speech perception, while talker characteristics are encoded separately.
由于包括说话者特征和语速在内的各种上下文因素，语音信号的声学结构极具变异性。为了解释听者适应这种变异性的能力，语音研究人员假定存在说话者和语速归一化过程。当前的研究考察了在语音感知过程中，感知系统是如何编码有关说话者和语速的信息的。实验1至3使用加纳（1974年）开发的快速分类范式来研究这个问题。这些实验的结果表明，关于音素身份的判断受到说话者和语速信息的影响：任一维度上的无关变异都会干扰音素分类。虽然语速分类也受音素变异的影响，但说话者分类不受影响。实验4考察了在不同的阻断条件下，说话者和语速变异对浊音边界的影响。结果表明，只有在特定条件下，当说话者变异出现在一组试验中时，说话者特征才会影响浊音边界。然而，无论一组试验中是否存在语速变异，语速变异都会影响浊音边界。这些实验的结果表明，在语音感知过程中，音素和语速信息是以一种整体的方式进行编码的，而说话者特征则是单独编码的。
