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

项目摘要/摘要 哺乳动物的耳蜗通过包括一个生理上的声音来实现其突出的表现特征。 当fiES波通过耳蜗线传播时，对其进行战略性放大的神经活动过程。作为一名 这种空间协调和非线性波放大fi的结果是，在一个特征上的耳蜗反应- 频率定位在很大程度上取决于生理状态和更多基底区域的反应。在……里面 对复杂声音的反应，不同频率的波沿着耳蜗非线性地相互作用，相互促进。 用一个按住另一个。与通常用于描述以下内容的一组独立操作的fi相比 耳蜗功能，不同的“耳蜗肌”(cochlearfilter)的反应是由非线性波相互作用强烈耦合的。 虽然非线性波相互作用在耳蜗声反应中起主要作用，但它们在编码复合体中的作用 听觉外周的声音--因此它们对中枢听觉机制的贡献--很差 理解，但在很大程度上被忽视了。 因此，了解非线性波的相互作用对于确定耳蜗如何编码生态- 逻辑上相关的声音和听觉外周对声音感知的作用。因为非线性波 相互作用取决于耳朵的健康状况，了解这些相互作用也是建立 耳蜗性损伤如何影响复杂声音的外周表征。更进一步，因为即使是温和的 感觉神经性听力损失会大大降低在听觉挑战情况下的行为表现，它是 很可能，非线性波相互作用是未被探索的机制的基础，这是 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复制的耳蜗模型 实验动物(目标1.a)和人类(目标1.b)的精确非线性波相互作用；(Ii)测试 假设非线性波相互作用不利于fi机制对声音进行声学编码 不利情况(目标2.a)；以及(3)确定非线性波的影响如何产生以及有何限制 在这个项目中阐明的相互作用是由流行的计算机听觉外周模型解释的 (目标2.b)。该项目的成果不仅将挑战和提高目前对人工耳蜗学的认识 功能，但也将fi和自然应用于改善听力障碍的模型，并在 确定新的耳蜗启发策略，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.