Doctoral Dissertation Research: Predictability and Recoverability of High Vowel Reduction in Speech

博士论文研究：语音中高元音减少的可预测性和可恢复性

• 批准号: 1524133
• 负责人: Lisa Davidson
• 金额: $ 1.08万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1524133&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Predictability; Recoverability

Human cognition relies on direct and indirect information to draw conclusions. Processes that rely on direct information are called bottom-up processes, where a conclusion is drawn based solely on the provided information; processes that rely on indirect information are called top-down processes, where elements such as context, pattern-recognition, and probability are used to form an expectation for a particular outcome. Studies have shown that a strong top-down process often blocks bottom-up processing of certain information available in the stimulus, but how the two types of processes interact is poorly understood. As an integral part of human cognition, language also shows interactions of top-down and bottom-up processes, where differences that are meaningful in one language may be readily ignored as uninformative in another. Language, therefore, is an excellent tool for shedding light on how the processing of direct and indirect information interacts in the mind.This research focuses on Japanese as a case study. The syllable structure of Japanese overwhelmingly follows a simple consonant-vowel structure. However, the process of high vowel reduction in Japanese, where unaccented vowels /i, u/ are weakened between two voiceless consonants (e.g., /suki/ [ski] 'like'), often results in the complete deletion of a vowel during speech production. However Japanese speakers often report perceiving a vowel between two consecutive voiceless consonants, even in the complete absence of a vowel (e.g., [ski] perceived as /suki/). It is unclear at this point what drives this misperception of apparently non-existent vowels, but there are two likely sources. The first is an indirect source. Given the simple syllable structure of Japanese, Japanese speakers are conditioned to expect a vowel after a consonant, in which case the misperception of a vowel would be the result of a strong top-down process. The alternative is a direct source. Because high vowel reduction is common in Japanese, Japanese speakers may be hypersensitive even to subtle acoustic information that indicates the presence of a vowel, in which case the perception of a vowel would be the result of a bottom-up process. A production experiment and a corpus study will first test what acoustic information for a weakened vowel exists in naturally produced speech. A perception experiment will then manipulate the direct and indirect information to test which of these Japanese listeners rely on more when perceiving a weakened vowel. The experimental results will inform a computational model, which investigates how a reliance on the direct and indirect cues might be learned. The experiments, together with the model, will lead to a deeper understanding of the extent in which bottom-up and top-down processes are shaped by experience both in language and more broadly in human cognition as a whole.

人类认知依赖于直接和间接信息来得出结论。依靠直接信息的过程称为自下而上的过程，其中仅根据提供的信息得出结论；依靠间接信息的过程称为自上而下的过程，在这种过程中，使用上下文，模式识别和概率等元素来形成对特定结果的期望。研究表明，强大的自上而下的过程通常会阻止刺激中可用的某些信息的自下而上处理，但是两种类型的过程相互作用的相互作用却很少。作为人类认知不可或缺的一部分，语言还显示了自上而下和自下而上的过程的相互作用，在某种语言中有意义的差异很容易被忽略为另一种语言。因此，语言是阐明直接和间接信息如何在思想中相互作用的绝佳工具。这项研究侧重于日语作为案例研究。日语的音节结构绝大多数遵循简单的辅音元音结构。但是，日语中元音降低的高度减少的过程，在两个无声的辅音（例如 / suki / [ski'like''）之间，元音元音 / i，u /的过程通常会削弱，通常会导致语音生产过程中元音的完全删除。然而，日本人经常报告说，即使完全没有元音（例如，被认为是 /suki /），即使在完全没有元音的情况下，连续两个连续的无声辅音之间的元音也是如此。目前尚不清楚是什么驱动了对显然不存在的元音的误解，但有两个可能的来源。第一个是间接来源。鉴于日本人的简单音节结构，日语说话者可以期待辅音后的元音，在这种情况下，对元音的误解将是强大的自上而下过程的结果。替代方案是直接来源。由于日语中的元音降低很常见，因此日本人的说话者甚至可能对表明元音的存在的微妙声明信息也很敏感，在这种情况下，元音的感知将是自下而上的过程的结果。一项生产实验和语料库研究将首先测试自然产生的元音中存在哪些声学信息。然后，一个感知实验将操纵直接和间接的信息，以测试这些日本听众在感知弱化的元音时更多地依靠。实验结果将为计算模型提供信息，该模型研究了如何学习对直接和间接提示的依赖。该实验与模型一起将更深入地了解自下而上和自上而下的过程的范围，以语言的经验以及整体上人类认知的更广泛的经验。