Spectro-temporal analysis in normal and impaired ears

描述(由申请人提供)：该项目的长期目标是更好地了解在听力正常和受损的复杂频谱-时间听觉背景下检测和识别信号的机制。这项拟议的工作包括三个特定的目标，研究正常和受损耳朵的频谱-时间加工。第一个特别的目标是更好地了解听力损失对频谱-时间过程的影响，这些过程是我们将S/N比率非常低时可以获得的声音信号片段“拼凑”在一起的能力的基础。在这里，我们将探讨感觉神经性听力损失对以下方面的影响：1)在语音和基音的感知中合并异步时频信息的能力；2)在跨频率语音线索的感知中合并同步时频信息的能力；以及3)在整合时频信息片段时背景噪声的促进作用(诱导效应)。第二个和第三个目标继续我们已建立的研究计划，调查跨频率共调在正常频谱-时间分析中的重要性。第二个目标是测试信道间和信道内的共调掩蔽释放(CMR)帐户。第三个目标是测试信道间和信道内的解调检测差异(CDD)。虽然最初对CMR和CDD的解释都是基于对跨通道信息的分析，但最近的研究对这种解释提出了质疑，并提出这种现象可能是通过呼吁外围的单通道机制来解释的。心理声学方法包括时间边缘操作、二分刺激呈现和信息掩蔽，以测试这些可能的解释。

DESCRIPTION (provided by applicant): The long-term aim of this project is a better understanding of mechanisms that underlie the ability to detect and recognize signals in complex spectro-temporal auditory backgrounds in normal and impaired hearing. The proposed work encompasses three specific aims investigating spectro-temporal processing in normal and impaired ears. The first specific aim is to obtain a better understanding of the effect of hearing loss on spectro-temporal processes that underlie our ability to "piece together" fragments of acoustical signals that are available when the S/N ratio is very poor. Here, we will explore the effects of sensori-neural hearing loss on 1) the ability to combine asynchronous spectro-temporal information in the perception of speech and pitch; 2) the ability to combine synchronous spectro-temporal information in the perception of across frequency speech cues; and 3) the facilitative effect of background noise when integrating fragments of spectro-temporal information (the induction effect). The second and third aims continue our established research program investigating the importance of across-frequency comodulation in normal spectro-temporal analysis. The second aim is to test between across-channel versus within channel accounts of comodulation masking release (CMR). The third aim is to test between across-channel versus within channel accounts of comodulation detection differences (CDD). Whereas the original interpretations of both CMR and CDD were based upon the analysis of across-channel information, recent research has challenged such interpretations, and has suggested that the phenomena may be accounted for by appealing only to peripheral, single-channel mechanisms. Psychoacoustical approaches involving temporal fringe manipulations, dichotic stimulus presentation, and informational masking are developed to test between these possible explanations.