AI 中文总结
本文构建含指数型位移依赖主动反馈的一维分布式极简耳蜗模型，重现耳蜗力学关键特征，其非线性响应优于三次非线性模型，揭示局部主动过程与纵向相互作用的协同作用。
AI 中文摘要
哺乳动物耳蜗的卓越灵敏度、压缩非线性和频率选择性源于主动过程，该过程可放大基底膜的被动机械响应。外毛细胞被广泛认为是耳蜗基底区域中该主动过程的主要效应器，且这种主动贡献随刺激强度增加而逐渐降低。受这些观察结果启发，本文研究了一个极简耳蜗模型，其中每个位置由受迫阻尼振荡器表示，具有指数型位移依赖的主动反馈；这些振荡器通过耳蜗液以及弹性和耗散性纵向相互作用耦合，形成一维分布式模型。该模型重现了耳蜗力学的关键特征，包括强度依赖的放大、压缩非线性、频率选择性、行波传播和相位积累。本文将其与简化的三次非线性模型进行了比较：尽管三次非线性可描述弱刺激下的响应，但在更高刺激强度下，它与指数模型出现偏差，无法重现向主要被动行为的逐渐过渡。纵向耦合会拓宽频率响应、改变行波轮廓并增加相位积累。所提出的模型为理解局部主动过程与纵向机械相互作用如何共同塑造耳蜗的非线性响应提供了简单的物理框架。
英文摘要
The remarkable sensitivity, compressive nonlinearity, and frequency selectivity of the mammalian cochlea arise from an active process that amplifies the passive mechanical response of the basilar membrane. Outer hair cells are widely regarded as the primary effectors of this active process in the basal regions of the cochlea. This active contribution progressively decreases with increasing stimulus level. Motivated by these observations, a minimal cochlear model is investigated in which each location is represented by a forced damped oscillator with an exponential displacement-dependent active feedback. The oscillators are coupled through the cochlear fluid and also by elastic and dissipative longitudinal interactions to form a one-dimensional distributed model. The model reproduces key features of cochlear mechanics, including level-dependent amplification, compressive nonlinearity, frequency selectivity, traveling-wave propagation, and phase accumulation. Comparison with a simplified cubic nonlinear model has been carried out. Even though the cubic nonlinearity describes the response for weak stimuli, at higher stimulus levels it deviates from the exponential model and fails to reproduce the gradual transition towards predominantly passive behavior. Longitudinal coupling broadens the frequency response, modifies the traveling wave profile, and increases phase accumulation. The proposed model provides a simple physical framework for understanding how local active processes and longitudinal mechanical interactions together shape the nonlinear response of the cochlea.
Comments27 pages, 8 figures
