Complex sound analysis in normal and impaired ears

描述（由申请人提供）：本项目的目的是确定听力困难的性质所经历的听众的能力，听到安静的声音，如纯音仍然相对较好。该项目的一个特别重点是老年听众，他们除了正常的听力图外，发现在背景声音中理解语音很困难。为了比较，患有耳蜗听力损失的年轻听众也将接受检查。该项目的框架围绕三个具体目标。第一个目标探讨了安静时正常阈值可能掩盖听觉神经水平的永久性神经功能障碍的可能性，这种情况与噪音暴露工作类似，表明尽管存在残余神经损伤，但声音过度暴露后的敏感性仍会恢复。这一目标将导致更好地描绘存在于表面上良好的听力中的声音处理缺陷。第二个目标是研究由复杂声音（如语音）诱发的听觉脑干反应（ABR）。这种类型的ABR测试的使用正在迅速增长，但仍有很多关于基本反应的理解。第二个目标的直接目标是研究与年龄相关的差异在言语诱发的ABR的特定情况下，但更广泛的目标是使用本研究作为一种工具，以更好地了解的多重因素，有助于在正常和耳蜗受损的听觉系统的言语诱发的ABR的生成。最后的目标有助于在日常听力环境中影响语音理解的因素的新视角，其中背景声音通常在时间和频率上波动，使得目标语音本身的一瞥在这些维度上以及在耳朵上动态变化。总之，这三个目标结合联合收割机提供了一系列平行的研究，将显着推进我们的理解复杂的声音，如语音在具有挑战性的听力环境中的处理，即使是听力相对较好的人。

DESCRIPTION (provided by applicant): The purpose of this project is to determine the nature of the hearing difficulties experienced by listeners whose ability to hear quiet sounds like pure tones is still relatively good. One particular focus of the project is on older listeners who, despte normal audiograms, find understanding speech in background sounds difficult. For comparison, younger listeners with cochlear hearing loss will also be examined. The framework of the project is structured around 3 Specific Aims. The first Aim explores the possibility that normal thresholds in quiet can belie permanent neural dysfunction at the level of the auditory nerve, a situation that parallels noise exposure work showing that recovery of sensitivity following acoustic over-exposure can occur despite residual nerve damage. This Aim will lead to a better delineation of the sound-processing deficits that exist in the face of apparently good hearing. The second Aim focuses on auditory brainstem responses [ABRs] evoked by complex sounds like speech. This type of ABR testing is rapidly growing in usage but much remains to be understood about the basic response. The immediate goal of the second Aim is to study the particular situation of age-related differences in the speech-evoked ABR, but the broader objective is to use this study as a vehicle to better understand the multiplicity of factors that contribute to the generation of the speech-evoked ABR both in the normal and cochlear-impaired auditory system. The final Aim contributes a new perspective on factors that affect speech understanding in everyday listening environments where the background sound is typically fluctuating in both time and frequency making the glimpses of target speech themselves dynamically vary across these dimensions as well as across ears. Together, these three Aims combine to provide a series of parallel studies that will significantly advance our understanding of the processing of complex sounds like speech in challenging listening environments, even for people with relatively good hearing.