Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health and Science University, Portland, Oregon, USA.
Biophys J. 2010 Sep 22;99(6):1687-95. doi: 10.1016/j.bpj.2010.07.004.
Sound processing begins at the peripheral auditory system, where it undergoes a highly complex transformation and spatial separation of the frequency components inside the cochlea. This sensory signal processing constitutes a neurophysiological basis for psychoacoustics. Wave propagation in the cochlea, as shown by measurements of basilar membrane velocity and auditory nerve responses to sound, has demonstrated significant frequency modulation (dispersion), in addition to tonotopic gain and active amplification. The physiological and physical basis for this dispersion remains elusive. In this article, a simple analytical model is presented, along with experimental validation using physiological measurements from guinea pigs, to identify the origin of traveling-wave dispersion in the cochlea. We show that dispersion throughout the cochlea is fundamentally due to the coupled fluid-structure interaction between the basilar membrane and the scala fluids. It is further influenced by the variation in physical and geometrical properties of the basilar membrane, the sensitivity or gain of the hearing organ, and the relative dominance of the compression mode at about one-third octave beyond the best frequency.
声音处理始于外围听觉系统，在那里，声音的频率成分在耳蜗内经历高度复杂的转换和空间分离。这种感觉信号处理构成了心理声学的神经生理学基础。正如基底膜速度的测量和听觉神经对声音的反应所显示的那样，声波在耳蜗中的传播除了具有音调增益和主动放大外，还具有显著的频率调制（频散）。这种频散的生理和物理基础仍然难以捉摸。本文提出了一个简单的分析模型，并使用豚鼠的生理测量进行了实验验证，以确定耳蜗中行波频散的起源。我们表明，整个耳蜗中的频散主要是由于基底膜和 scala 液之间的耦合流固相互作用所致。它还受到基底膜物理和几何特性、听觉器官灵敏度或增益以及最佳频率以外约三分之一八度处压缩模式相对优势的变化的影响。
