The Relative Amplitude of Vowel Formants

描述（由申请人提供）：本研究的长期目标是表征语音片段的相对强度在元音和辅音的听觉处理中的作用，在更大的韵律域（如单词）中。强度在语音处理中的作用还没有被系统地探讨过，其确切的贡献也是未知的。这个应用程序侧重于元音，并研究元音共振峰的相对振幅，作为音位区分的线索。两个具体目的是：1)检查在选定的共发音和孤立元音的产生中共振峰相对振幅的声学模式；2)研究形成峰水平对听者判断元音质量和可理解性的听觉影响。提出的声学研究是House & Fairbanks（1953）对元音强度的早期研究（F1, F2, F3, F4）的延伸。它的目标是确定元音强度是否以及如何分布在构音水平上，以及这种分布是否随辅音上下文而变化。本知觉研究调查了听者对孤立元音和单词语境中元音共振峰相对振幅变化的反应。试点数据表明，共振峰的强度是元音分类的线索。24名受试者将被用于进一步测试更多美式英语元音的形成峰水平模式。这些模式的声学和感知相关性旨在提供基本的理解，当时间和环境因素减少了元音线索在自然语言中的处理时间时，元音线索是如何整合到单个感知中的。由于声音强度的动态范围已被证明对助听器的性能有巨大的影响，并且由于大约一半的65岁以上的美国人可能是助听器放大的候选人，这项研究对这些人的医疗保健质量有影响。

DESCRIPTION (provided by applicant): The long-term objective of this research is to characterize the role of relative intensity of speech segments in the auditory processing of vowels and consonants within larger prosodic domains such as words. The role of intensity in speech processing has not been explored in a systematic way and its exact contribution is unknown. This application focuses on vowels and investigates the relative amplitude of vowel formants as a cue to making phonemic distinctions. Two specific aims are: 1) to examine the acoustic pattern of the relative amplitude of formants in the production of selected coarticulated and isolated vowels; and 2) to examine the auditory effect of manipulation of formant levels on listeners' decision about vowel quality and intelligibility of words. The proposed acoustic study is an extension of an early work on vowel intensity by House & Fairbanks (1953) to formant levels (F1, F2, F3, F4). Its goal is to establish whether and how vowel intensity is distributed over formant levels and whether this distribution varies with consonantal context. The proposed perception study investigates listeners' response to changes in the relative amplitude of formants for isolated vowels and for vowels in word context. Pilot data show that intensity of formants is a cue to vowel categorization. 24 subjects will be used to further test the patterns of formant levels in a larger set of American English vowels. The acoustic and perceptual relevance of these patterns aims to provide basic understanding about the way the vowel cues are integrated in a single percept when temporal and contextual factors reduce time for their processing in natural speech. Since the dynamic range in the intensity of sounds has been shown to have a dramatic effect on hearing aid performance, and since around one half of the Americans over the age of 65 may be candidates for amplification this research has implications for the quality of health care for these individuals.