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理解正常和受损听力者在复杂的光谱-时间听觉背景下检测和识别信号的能力的机制。提出的工作包括三个具体目标调查光谱-时间处理在正常和受损的耳朵。第一个具体目标是更好地理解听力损失对光谱-时间过程的影响，这是我们在信噪比非常低时“拼凑”声音信号片段的能力的基础。在这里，我们将探讨感觉神经性听力损失对1)语音和音高感知中结合异步光谱-时间信息的能力的影响；2)在跨频率语音线索感知中结合同步光谱-时间信息的能力；背景噪声对光谱-时间信息片段整合的促进作用（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，调查跨频率调制在正常光谱-时间分析中的重要性。第二个目标是测试跨信道与信道内调制掩蔽释放（CMR）帐户之间的关系。第三个目标是测试跨信道与信道内调制检测差异（CDD）。虽然CMR和CDD的原始解释都是基于跨通道信息的分析，但最近的研究对这种解释提出了挑战，并表明这种现象可能仅通过吸引外围的单通道机制来解释。心理声学方法包括时间条纹操作、双重刺激呈现和信息掩蔽，以测试这些可能的解释之间的差异。

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.