Temporal weighting of auditory spatial cues

项目摘要 本研究将探讨听众如何在不同类型的听觉系统中将联合收割机的听觉空间信息结合起来， 双耳线索（耳间时间差[ITD]和耳间水平差[ILD]），随着时间的推移， 频率，以便更好地了解空间听觉的动态过程， 混响环境。ITD和ILD提供了一组主要的线索，使听众能够定位 空间中的声音，并隔离竞争声源。在理想的情况下，这些线索在不同的情况下是一致的。 频率和两种提示类型之间的差异，因此提供了关于 听觉空间然而，回声和混响会随着时间的推移扭曲这些线索，降低定位 言语理解。而普通的双耳系统通过强调鲁棒性来进行补偿 声音的各个方面（如开始时的ITD），老年人，听力受损或使用 耳蜗植入物在存在回声和混响的情况下仍然遇到困难。 识别这些听觉处理缺陷的具体性质是困难的，因为我们所知甚少。 听力正常的人的补偿机制。过去的研究 研究了空间线索的影响如何随着声音的时间进程而变化（从而 强调声音开始），并跨越其频谱（通常强调空间 低频携带的信息），但一个关键问题仍然没有答案： 双耳处理的频率或多个频率时不同？相反，做 高频和低频的相对贡献在刺激持续时间内变化？的 拟议研究的具体目标通过绘制听众的时间进程来解决这个问题。 对不同频率、带宽的声音的耳间差异的敏感性，以及 双耳线索频率。听者会用时变的声音来判断声音的空间位置 ITD和/或ILD，以及多元回归将用于测量这些判断的依赖性 ITD和/或ILD。回归系数将用于构建时间加权函数 （TWF），说明ITD和ILD随时间整合的神经机制的动态， 跨频率平行实验将使用听觉皮层和下皮层的神经成像， 丘，沿着与计算机模型的听觉周边，在努力确定在什么水平 这些效应发生的听觉过程。

Project Summary This research will examine how listeners combine auditory spatial information across different types of binaural cues (interaural time differences [ITD] and interaural level differences [ILD]), over time, and across frequency in order to better understand the dynamic processes underlying spatial hearing in reverberant environments. ITD and ILD provide the major set of cues that allow listeners to localize sounds in space and to segregate competing sound sources. In ideal situations, the cues agree across frequency and between the two cue types, and therefore provide redundant information about auditory space. Echoes and reverberation, however, distort these cues over time, degrading localization and speech understanding. Whereas the normal binaural system compensates by emphasizing robust aspects of the sound (such as ITD at onset), listeners who are aging, hearing-impaired, or using cochlear implants continue to experience difficulty in the presence of echoes and reverberation. Identifying the specific nature of these auditory processing deficits is difficult because so little is known about the compensatory mechanisms at work in normal-hearing listeners. Past research has investigated how the influence of spatial cues varies over the time-course of a sound (thereby emphasizing sound onsets), and across its frequency spectrum (typically emphasizing spatial information carried by low frequencies) but a key question remains unanswered: does the time-course of binaural processing vary across frequency or when multiple frequencies are present? Conversely, do the relative contributions of high and low frequencies change over the duration of a stimulus? The specific aims of the proposed study address this question by mapping the time-course of listeners' sensitivity to interaural differences for sounds varying in frequency, bandwidth, and the agreement of binaural cues across frequency. Listeners will judge the spatial positions of sounds with time-varying ITD and/or ILD, and multiple regression will be used to measure the dependence of those judgments on ITD and/or ILD. Regression coefficients will be used to construct temporal weighting functions (TWFs) that illustrate the dynamics of neural mechanisms for integration of ITD and ILD over time and across frequency. Parallel experiments will use neuroimaging of the auditory cortex and inferior colliculus, along with computer models of the auditory periphery, in an effort to identify at what level of auditory processing these effects take place.