Sohmer Haim
Department of Medical Neurobiology (Physiology), The Hebrew University-Hadassah Medical School, PO Box 12272, 91120, Jerusalem, Israel,
Eur Arch Otorhinolaryngol. 2015 Mar;272(3):531-5. doi: 10.1007/s00405-014-3045-z. Epub 2014 Apr 17.
Air conduction (AC) is accompanied by displacements of the two cochlear windows, bulk fluid flow between them, a pressure difference across the basilar membrane, leading to a passive traveling wave along the membrane, which activates the cochlear amplifier and enhances the displacements. AC interacts with bone conduction (BC) stimulation, so that it has been assumed that BC stimulation also involves a passive traveling wave. However, several clinical conditions and experimental manipulations provide evidence that a passive traveling wave may not be involved in BC stimulation at low intensities. Soft tissue conduction (STC) (also called non-osseous bone conduction) involves applying the bone vibrator to soft tissues on the head, neck and thorax, eliciting auditory sensation. STC stimulation probably does not involve a passive traveling wave. This review presents clinical conditions and experimental manipulations which assess the contributions of AC, BC and STC stimulation to the passive traveling wave. Evidence from the clinic (otosclerosis, round window atresia) and from the laboratory (holes in the wall of the inner ear, immobilization of the ossicular chain and the windows, discontinuity of the chain, measurement of basilar membrane displacements in the absence of the cochlear amplifier) lead to the conclusion that a passive basilar membrane traveling wave may not be involved in stimulation at low sound intensities. It is suggested that at low sound levels, the outer hair cell cochlear amplifier may not be activated by a passive traveling wave, but may be directly activated by the fast cochlear fluid pressures induced by AC, BC and STC stimulation. On the other hand, at high intensities, the cochlea is activated by the slow passive traveling wave.
气导（AC）伴随着两个耳蜗窗的位移、它们之间的大量流体流动、基底膜上的压力差，导致沿膜的被动行波，这激活了耳蜗放大器并增强了位移。气导与骨导（BC）刺激相互作用，因此有人认为骨导刺激也涉及被动行波。然而，一些临床情况和实验操作提供了证据，表明在低强度时骨导刺激可能不涉及被动行波。软组织传导（STC）（也称为非骨性骨导）涉及将骨振动器应用于头部、颈部和胸部的软组织，引发听觉感受。软组织传导刺激可能不涉及被动行波。本综述介绍了评估气导、骨导和软组织传导刺激对被动行波贡献的临床情况和实验操作。来自临床（耳硬化症、圆窗闭锁）和实验室（内耳壁上的孔、听骨链和窗的固定、链的中断、在没有耳蜗放大器的情况下测量基底膜位移）的证据得出结论，在低声强时，被动的基底膜行波可能不参与刺激。有人认为，在低声强时，外毛细胞耳蜗放大器可能不会被被动行波激活，而是可能被气导、骨导和软组织传导刺激引起的快速耳蜗流体压力直接激活。另一方面，在高强度时，耳蜗由缓慢的被动行波激活。
