Dynamic Effects in Peripheral Auditory Processing

描述（由申请人提供）：本提案的长期目标是进一步了解外周听觉处理的感知后果以及正常和受损听力中的传出或自上而下效应。该项目有三个主要目标。目的1是提供行为和生理估计的假设影响内侧橄榄耳蜗（MOC）传出系统对基底膜（BM）的增益和压缩在人类，并确定其后果的时间处理在个别频率通道使用前向掩蔽。这些措施将在听力正常的听众和听众与感音神经性听力损失。目的2将研究从通道内扩展到跨通道时间加工，研究外周滤波和传出控制对复杂声音谱时加工的影响。工作假设是，随着听力损失，BM滤波的变化导致沿BM的相对延迟沿着的变化，这不能完全由神经可塑性补偿。跨通道时间同步在我们感知分离复杂环境中竞争声音的能力中起着至关重要的作用，因此感知同步的中断在嘈杂和具有挑战性的声学背景中可能特别有害。根据这一目标的实验将测量跨频率的声音的时间感知，在时间分辨率和敏锐度方面，以及在同步性的主观判断方面，以测试跨频率的时间感知随听力损失而变化的假设。目标3将采用目标1和目标2中获得的基本心理物理学知识，并将其应用于噪声背景中的语音感知。句子的语音清晰度将在稳定噪声、波动噪声和单个说话者干扰的条件下测量，其中系统延迟在频率上施加。安静时的语音感知对频率上的时间变化具有显著的鲁棒性。我们的工作假设是，无论是通过信号处理或听力损失的结果施加的时间的模糊，将产生更严重的赤字在嘈杂的情况下，从掩蔽的目标的感知隔离的语音清晰度是必需的。这些结果将进一步加深我们对传出刺激如何影响外周听觉处理的理解，以及听力损失如何影响我们对声音的感知以及我们在具有挑战性的声学环境中进行交流的能力。了解周边听觉处理如何影响通道内和跨通道的时间感知，可能会导致新的助听器信号处理算法，补偿听力损失引起的跨通道的时间变化。 公共卫生相关性：这项提案中的工作旨在进一步了解大脑的“自上而下”影响如何影响内耳处理声音的方式，以及这种处理如何影响听力正常和听力困难的人感知声音和语音的方式。对听力损失引起的耳朵变化如何影响感知的更好理解应该会导致设计助听器的新方法和改进方法。

DESCRIPTION (provided by applicant): The long-term goal of this proposal is to further our understanding of the perceptual consequences of peripheral auditory processing and efferent, or top-down, effects in normal and impaired hearing. The project has three main aims. Aim 1 is to provide behavioral and physiological estimates of the hypothesized effects of the medial olivocochlear (MOC) efferent system on basilar-membrane (BM) gain and compression in humans, and to determine their consequences for temporal processing within individual frequency channels using forward masking. These measures will be undertaken in both normal-hearing listeners and listeners with sensorineural hearing loss. Aim 2 extends the investigation from within-channel to across-channel temporal processing to study the effects of peripheral filtering and efferent control on the spectro-temporal processing of complex sounds. The working hypothesis is that changes in BM filtering with hearing loss lead to changes in the relative latencies along the BM, which are not fully compensated by neural plasticity. Across-channel temporal synchrony plays a crucial role in our ability to perceptually segregate competing sounds in complex environments, so a disruption of perceived synchrony may be particularly detrimental in noisy and challenging acoustic backgrounds. Experiments under this aim will measure the temporal perception of sounds across frequency, in terms of temporal resolution and acuity, as well as in terms of subjective judgments of synchrony to test the hypothesis that across-frequency temporal perception changes with hearing loss. Aim 3 will take the basic psychophysical knowledge gained in Aims 1 and 2 and apply it to speech perception in noisy backgrounds. Speech intelligibility of sentences will be measured in steady noise, fluctuating noise, and single- talker interference in conditions where systematic delays are imposed across frequency. Speech perception in quiet has been shown to be remarkably robust to temporal asynchronies across frequency. Our working hypothesis is that temporal asynchronies, whether imposed through signal processing or as a result of hearing loss, will produce much more serious deficits in speech intelligibility in noisy situations, where perceptual segregation of the target from the masker is required. The results will further our understanding of how peripheral auditory processing is affected by efferent stimulation, and how changes in peripheral processing due to hearing loss affect our perception of sound and our ability to communicate in challenging acoustic environments. Understanding how peripheral auditory processing influences within- and across-channel temporal perception may lead to novel signal-processing algorithms for hearing aids that compensate for the across-channel temporal changes induced by hearing loss. PUBLIC HEALTH RELEVANCE: The work in this proposal aims to further our understanding of how "top-down" influences from the brain affect the way sound is processed in the inner ear, and how that processing affects the way people with normal hearing and people with hearing difficulties perceive sound and speech. Improved understanding of how perception is affected by changes in the ear due to hearing loss should lead to new and improved methods for designing hearing aids.