ACOUSTIC AND PERCEPTUAL INVARIANCE IN SPEECH

本研究的主要目的是阐明声音的属性是如何映射到词汇上的。目前的建议侧重于表征语音类别的结构，包括边界约束和内部结构，以及这些类别在词汇形式上的映射。将探讨语音类别的边界约束，以确定被称为标准属性的特定声学属性是否在多种变异性来源中保持稳定，包括语言的影响、音位对比的存在与否、音段（辅音或元音）的内在性质的影响、二次发音对声学属性出现的影响、以及退化同化和元音环境的影响。语音类别内部结构的“形状”将通过探索语言对语音类别表示的“首选”或原型区域的程度来绘制；标准属性与与之相关的值“家族”之间的关系，以定义该类别的最佳范例；以及标准属性的“最佳范例”范围可能受到说话速率和其他声学参数存在的影响的程度。语音类别到词汇形式的映射将通过评估声学变化是否以及以何种方式影响语音类别结构最终影响词汇形式来研究。实验将探讨有或没有定义语音类别的声学变体的作用，语音位置和音节重音的影响，以及先验词汇激活（自上而下的加工）对词汇获取中出现的次语音效应的影响。研究方法包括语音的声学分析和定量算法的开发，自然语音的计算机编辑，以便进行语音感知和词汇决策实验。这项研究应该提供对语音处理系统的更好理解，以及它如何与更高层次的语言处理接口。描述正常成人的言语处理过程是理解言语和语言病理的基础，特别是在成人中，但也在儿童中。

The broad goal of this research is to explicate how the properties of sound map on the lexicon. The current proposal focuses on a characterization of the structure of phonetic categories, including both boundary constraints and internal structure, and the mapping of these categories on to lexical form. Boundary constraints of phonetic categories will be explored to determine whether particular acoustic properties called criterial attributes remain stable across a number of sources of variability including the influence of language, the presence or absence of phonemic contrast, the influence of the intrinsic nature of the sound segment (consonant or vowel), the influence of a secondary articulation on the emergence of an acoustic property, and the influence of regressive assimilation and vowel environment. The 'shape' of the internal structure of phonetic categories will be charted by exploring the extent to which languages have 'preferred' or prototypical region for the representation of a phonetic category; the relationship between a criterial attribute and the 'family' of values associated with it to define the best exemplar for that category; and the extent to which to which a range of 'best exemplars' of a criterial attribute may be influenced by speaking rate and the presence of other acoustic parameters. The mapping of phonetic categories on to lexical form will be investigated by assess whether and in which ways the acoustic variations which to and affect phonetic category structure ultimately impact lexical form. Experiments will investigate the role of acoustic variants that do or do not define phonetic categories, the influence of phonetic position and syllable stress, and the influence of prior lexical activation (top-down processing) on the emergence of subphonetic effects on lexical access. Research methods include acoustic analyses of speech and development of quantitative algorithms, computer-editing of natural speech in order to conduct both speech perception and lexical decision experiments. This research should provide a greater understanding of the speech processing system and how it interfaces with higher levels of language processing. Characterizing the speech processing of normal adults serves as the basis for the understanding of pathologies of speech and language, particularly in adults, but also in children.