Nonlinear wave interactions in the cochlea and their application to sound processing

项目摘要/摘要 哺乳动物耳蜗通过包括生理上的vul， 这是一个可生成的主动过程，当波通过耳蜗螺旋传播时，它会策略性地放大波。作为 这种空间协调和非线性波放大的结果，耳蜗响应的一个特征- 频率位置在很大程度上取决于生理状态和更多基底区域中的响应。在 对复杂声音的反应，不同频率的波沿耳蜗沿着非线性地相互作用，相互支持， 用另一个压一个。与通常用于描述独立运营的过滤器的银行相反， 耳蜗功能，不同的“耳蜗滤波器”的响应通过非线性波相互作用强烈耦合。 虽然非线性波相互作用在耳蜗反应中起主要作用，但它们在编码复合物中的作用 听觉外围的声音--以及因此它们对中枢听觉机制的贡献-- 被理解和忽视。 因此，理解非线性波的相互作用对于建立耳蜗如何编码生态系统至关重要。 逻辑上相关的声音和听觉周边对声音感知的作用。因为非线性波 相互作用取决于耳朵的健康，理解这些相互作用也是建立 耳蜗损伤如何影响复杂声音的外周表征。此外，因为即使是温和的 感音神经性听力损失大大降低了在声学挑战性情况下的行为表现， 很可能，非线性波相互作用的基础未探索的机制，为出色的性能， 健康的耳朵 我的项目将通过以下方式解决这些问题：（i）从实验数据中推导出一个耳蜗模型， 在实验室动物（目标1.a）和人类（目标1.b）中精确的非线性波相互作用;（ii）测试 假设非线性波相互作用是声学上编码声音的有益机制的基础， 不利情况（目标2.a），以及（iii）确定非线性波的影响如何以及有哪些限制 在这个项目中阐明的相互作用是由流行的计算机模型的听觉周边 (Aim 2.b）。该项目的结果不仅将挑战和改善目前对耳蜗的理解， 功能，但也将发现自然应用于改善听力障碍模型， 确定新颖的耳蜗启发策略，以提高辅助听力技术的性能。

Project Abstract/Summary The mammalian cochlea achieves its outstanding performance characteristics by including a physiologically vul- nerable active process that strategically amplifies waves as they propagate through the cochlear spiral. As a result of this spatially coordinated and nonlinear wave amplification, the cochlear response at one characteristic- frequency location largely depends upon the physiological status and the response in more basal regions. In response to complex sounds, waves of different frequency nonlinearly interact along the cochlea, mutually sup- pressing one with the other. In contrast to a bank of independently operating filters commonly used to depict cochlear function, the responses of distinct “cochlear filters" are strongly coupled by nonlinear wave interactions. Although nonlinear wave interactions play a major role for the cochlea response, their role for encoding complex sounds in the auditory periphery—and consequently their contribution to central auditory mechanisms—is poorly understood and largely ignored. Understanding nonlinear wave interactions is hence essential to establish how the cochlea encodes eco- logically relevant sounds and the role of the auditory periphery for sound perception. Because nonlinear wave interactions depend upon the health of the ear, understanding these interactions is fundamental also to establish how cochlear impairment affects the peripheral representation of complex sounds. Further, because even mild sensorineural hearing loss greatly degrades behavioral performance in acoustically challenging situations, it is likely that nonlinear wave interactions underlie unexplored mechanisms for the outstanding performance of the healthy ear. My project will tackle these issues by: (i) deriving from the experimental data a cochlear model that reproduces accurately nonlinear wave interactions in laboratory animals (Aim 1.a) and humans (Aim 1.b); (ii) testing the hypothesis that nonlinear wave interactions underly beneficial mechanisms to encode sounds in acoustically adverse situations (Aim 2.a), and (iii) determining how and with what limitations the effects of nonlinear wave interactions elucidated in this project are accounted for by popular computer models of the auditory periphery (Aim 2.b). The results of this project will not only challenge and improve the current understanding of cochlear function for hearing, but will also find natural application in improving models of hearing impairment, and in determining novel cochlear-inspired strategies to improve the performance of assistive hearing technology.