Distortion-product source unmixing: A test of the two-mechanism model for DPOAE generation
Distortion-product source unmixing: A test of the two-mechanism model for DPOAE generation
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DOI：
10.1121/1.1334597
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发表时间：
2001-02-01
影响因子：
2.4
通讯作者：
Shera, CA
中科院分区：
文献类型：
--
作者：
Kalluri, R;Shera, CA
本文测试了失真产物耳声发射（DPOAE）产生的“双机制模型”的关键预测。双机制模型认为，下边带DPOAE构成了一个混合的发射所产生的不仅是从两个不同的耳蜗位置（现在已经很好地建立），但更重要的是，由两个根本不同的机制：非线性失真引起的行波和线性相干反射了预先存在的微机械阻抗扰动。该模型预测：（1）由频率缩放刺激诱发的DPOAE（例如，在固定f（2）/f（1）下）可以分解成假定的失真源分量和反射源分量，其相位的频率依赖性与假定的产生机制一致;（2）总DPOAE的假定反射源分量与反射源发射紧密匹配（例如，低水平刺激频率发射）。通过使用两种完全不同的方法将DPOAE分解为组件来测试这些预测：（a）使用失真产品频率附近的第三个音调选择性抑制假定的反射源和（B）频谱平滑（或等效地，时域开窗）。虽然这两种方法以非常不同的方式分解，但它们产生相似的DPOAE分量。两个DPOAE分量的性质与双机制模型的预测一致。(C)2001年，美国声学学会。
This paper tests key predictions of the "two-mechanism model" for the generation of distortion-product otoacoustic emissions (DPOAEs). The two-mechanism model asserts that lower-sideband DPOAEs constitute a mixture of emissions arising not simply from two distinct cochlear locations las is now well established) but, more importantly, by two fundamentally different mechanisms: nonlinear distortion induced by the traveling wave and linear coherent reflection off pre-existing micromechanical impedance perturbations. The model predicts that (1) DPOAEs evoked by frequency-scaled stimuli (e.g., at fixed f(2)/f(1)) can be unmixed into putative distortion- and reflection-source components with the frequency dependence of their phases consistent with the presumed mechanisms of generation; (2) The putative reflection-source component of the total DPOAE closely matches the reflection-source emission (e.g., low level stimulus-frequency emission) measured at the same frequency under similar conditions. These predictions were tested by unmixing DPOAEs into components using two completely different methods: (a) selective suppression of the putative reflection source using a third tone near the distortion-product frequency and (b) spectral smoothing (or, equivalently, time-domain windowing). Although the two methods unmix in very different ways, they yield similar DPOAE components. The properties of the two DPOAE components are consistent with the predictions of the two-mechanism model. (C) 2001 Acoustical Society of America.