Acoustic cues in auditory pattern analysis

描述（由申请人提供）：本提案的总体目标是识别和表征听觉过程，该听觉过程限制对不同水平刺激的频谱线索的检测和区分，包括正常听力和听力受损的听众。目的1采用心理声学的轮廓分析范式，考察刺激水平波动对频谱形状辨别的影响。为了限制绝对水平线索的使用，在频谱形状辨别的心理物理测试中经常引入水平漫游，但初步数据表明，这种操纵在1kHz以上比在1kHz以下具有更大的效果。这样的结果将对我们认为我们所知道的光谱形状敏感性有重要的影响。目的二是探讨语音分析与元音识别的关系，包括语音水平波动对元音识别的潜在影响。在这一目标的实验将澄清这两种范式之间的关联，往往被认为是密切相关的，在何种程度上心理物理数据的频谱形状歧视通知我们的理解的言语感知。目的3探讨了时间精细结构在掩蔽语音感知中的作用，重点是波动噪声中的语音识别。鉴于最近的研究文献中提供的时间精细结构的听力调制噪声中起着关键作用的想法，支持拟议的实验引入控制条件和测试似是而非的替代假设，尚未得到严格的评估。考虑到最近对开发保留精细定时线索的耳蜗植入技术的兴趣，这个问题特别相关。目标4开发了新的线索范式，有可能为我们从波动背景中提取信号的能力提供新的见解。这种方法的一个目标是更好地理解观察掩蔽释放所需的先决条件。预计在这四个目标中提出的工作将澄清随机电平波动在处理自然声音中存在的频谱线索中的作用，例如背景噪声中的语音识别。

DESCRIPTION (provided by applicant): The overarching goal of this proposal is to identify and characterize the auditory processes that limit detection and discrimination of spectral cues for stimuli that vary in level, including both normal- hearing and hearing-impaired listeners. Aim 1 examines the effect of stimulus level fluctuation on spectral shape discrimination using the psychoacoustic paradigm of profile analysis. Level rove is often introduced in psychophysical tests of spectral shape discrimination in order to limit the use of absolute level cues, but preliminary data indicate that this manipulation has greater effect above than below 1 kHz. Such a result would have important implications for what we think we know about sensitivity for spectral shape. Aim 2 concerns the relationship between profile analysis and vowel perception, including potential effects of level fluctuation on vowel discrimination. Experiments in this aim will clarify the association between these two paradigms, often assumed to be closely related, and the extent to which psychophysical data on spectral shape discrimination inform our understanding of speech perception. Aim 3 explores the role of temporal fine-structure in masked speech perception, with emphasis on speech recognition in fluctuating noise. Whereas recent studies in the literature provide support for the idea that temporal fine-structure plays a key role in hearing in modulated noise, the proposed experiments introduce control conditions and test plausible alternative hypotheses that have not yet been rigorously evaluated. This issue is particularly pertinent given recent interest in developing cochlear implant technology that preserves fine timing cues. Aim 4 develops novel cuing paradigms that have the potential to provide new insights about our ability to extract signals from fluctuating backgrounds. One goal of this approach is to develop a greater understanding of the preconditions necessary for observing masking release. It is anticipated that the work proposed in these four aims will clarify the role of random level fluctuation in the processing of spectral cues present in natural sounds, such as those underlying speech recognition in background noise.