Davis H
Hear Res. 1983 Jan;9(1):79-90. doi: 10.1016/0378-5955(83)90136-3.
A model for cochlear mechanics is proposed to take account of its two systems, one passive and one active. The classical passive system stimulates the inner hair cells directly at levels above about 40 dB SL. At intensities below about 60 dB an active process, the 'cochlear amplifier' (CA), somehow provides additional energy that enhances the vibration of a narrow segment of the basilar membrane near the apical foot of the familiar, traveling wave envelope. The outer hair cells are essential for CA. The active system acts like a high-Q acoustic resonator, and it accounts for the great sensitivity and sharp tuning expressed by the 'tips' of neural tuning curves. The tips are selectively vulnerable to anoxia, noise exposure and other trauma. The CA model explains the detection of small differences in time as well as in frequency, the dual character of the electrocochleogram, recruitment of loudness in cochlear hearing impairment, the long latency of normal neural responses near threshold, acoustic emissions (both stimulated and spontaneous) and the locus of TTS in the frequency range above the exposure tone. Both the classical high-intensity system and the active low-level CA system are highly nonlinear and they combine to compress the great dynamic range of hearing into a much narrower range of mechanical movement of the cilia of the inner hair cells. The mechanism of CA is unknown, and the problem remains of how its action can be triggered by submolecular movements near threshold.
提出了一种用于解释耳蜗力学的模型，该模型考虑了耳蜗的两个系统，一个是被动系统，另一个是主动系统。经典的被动系统在高于约40 dB SL的水平时直接刺激内毛细胞。在低于约60 dB的强度下，一个主动过程，即“耳蜗放大器”（CA），以某种方式提供额外的能量，增强了在熟悉的行波包络顶端附近基底膜狭窄段的振动。外毛细胞对CA至关重要。主动系统的作用类似于一个高Q值的声学谐振器，它解释了神经调谐曲线“尖端”所表现出的高灵敏度和尖锐调谐。这些尖端对缺氧、噪声暴露和其他损伤具有选择性易损性。CA模型解释了对时间和频率微小差异的检测、耳蜗电图的双重特征、耳蜗性听力障碍中响度的重振、阈值附近正常神经反应的长潜伏期、声发射（包括刺激声发射和自发性声发射）以及暴露音调以上频率范围内暂时性阈移的位点。经典的高强度系统和主动的低水平CA系统都是高度非线性的，它们共同作用将听力的巨大动态范围压缩到内毛细胞纤毛更窄的机械运动范围内。CA的机制尚不清楚，问题仍然是其作用如何能由阈值附近的亚分子运动触发。
