Acoustic cues in auditory pattern analysis

描述(由申请人提供)：本提案的主要目标是确定和描述限制对水平不同的刺激的光谱线索的检测和识别的听觉过程，包括听力正常的和听力受损的听者。目的1利用轮廓分析的心理声学范式，研究刺激水平波动对频谱形状辨别的影响。水平漫游经常被引入到光谱形状辨别的心理物理测试中，以限制绝对水平线索的使用，但初步数据表明，这种操纵在1 kHz以上比在1 kHz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的敏感性有重要的影响。目的2研究侧写分析与元音感知之间的关系，包括水平波动对元音辨别的潜在影响。这一目的的实验将阐明这两种通常被认为密切相关的范式之间的联系，以及关于频谱形状辨别的心理物理数据在多大程度上有助于我们对言语知觉的理解。目的3探讨时间精细结构在掩蔽语音感知中的作用，重点研究波动噪声环境下的语音识别。虽然最近的文献研究支持时间精细结构在调制噪声中对听力起关键作用的观点，但拟议的实验引入了控制条件，并测试了尚未得到严格评估的可信的替代假设。考虑到最近人们对开发保留精细计时线索的人工耳蜗植入技术的兴趣，这个问题尤其相关。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了解观察掩蔽释放所必需的前提条件。预计这四个目标中提出的工作将阐明随机水平波动在处理自然声音中存在的光谱线索中的作用，例如背景噪声中潜在的语音识别。

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.