Shera C A, Zweig G
Theoretical Division, Los Alamos National Laboratory, New Mexico 87545.
J Acoust Soc Am. 1991 Mar;89(3):1290-305. doi: 10.1121/1.400654.
A number of authors [de Boer and Viergever, Hear. Res. 13, 101-112 (1984); de Boer et al., in Peripheral Auditory Mechanisms (Springer-Verlag, Berlin, 1986); Hear. Res. 23, 1-7 (1986); Viergever, in Auditory Frequency Selectivity (Plenum, New York, 1986), pp. 31-38; Kaernbach et al., J. Acoust. Soc. Am. 81, 408-411 (1987)] have argued that backward-traveling waves, in striking contrast to waves traveling forward towards the helicotrema, suffer appreciable reflection as they move through the basal turns of the cochlea. Such reflection, if present, would have important consequences for understanding the nature and strength of otoacoustic emissions. The apparent asymmetry in reflection of cochlear waves is shown, however, to be an artifact of the boundary condition those authors impose at the stapes: conventional cochlear models are found not to generate reflections of waves traveling in either direction even when the wavelength changes rapidly and the WKB approximation breaks down. Although backward-traveling waves are not reflected by the secular variation of the geometrical and mechanical characteristics of the cochlea, they are reflected when they reach the stapes. The magnitude of that boundary reflection is computed for the cat and shown to be a large, rapidly varying function of frequency.
一些作者[德布尔和维耶热弗，《听觉研究》13，101 - 112（1984）；德布尔等人，载于《外周听觉机制》（施普林格出版社，柏林，1986年）；《听觉研究》23，1 - 7（1986）；维耶热弗，载于《听觉频率选择性》（普伦出版社，纽约，1986年），第31 - 38页；凯尔恩巴赫等人，《美国声学学会杂志》81，408 - 411（1987）]认为，与朝着蜗孔向前传播的波形成鲜明对比的是，向后传播的波在通过耳蜗基部转弯处时会遭受明显的反射。如果存在这种反射，对于理解耳声发射的性质和强度将产生重要影响。然而，耳蜗波反射中明显的不对称性被证明是这些作者在镫骨处施加的边界条件造成的假象：发现传统的耳蜗模型即使在波长快速变化且WKB近似失效时，也不会产生沿任何一个方向传播的波的反射。尽管向后传播的波不会因耳蜗几何和机械特性的长期变化而反射，但当它们到达镫骨时会被反射。计算了猫的这种边界反射的幅度，并表明它是频率的一个大的、快速变化的函数。
