Department of Speech, Language, and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA.
J Acoust Soc Am. 2021 Oct;150(4):2817. doi: 10.1121/10.0006662.
There are psychoacoustic methods thought to measure gain reduction, which may be from the medial olivocochlear reflex (MOCR), a bilateral feedback loop that adjusts cochlear gain. Although studies have used ipsilateral and contralateral elicitors and have examined strength at different signal frequencies, these factors have not been examined within a single study. Therefore, basic questions about gain reduction, such as the relative strength of ipsilateral vs contralateral elicitation and the relative strength across signal frequency, are not known. In the current study, gain reduction from ipsilateral, contralateral, and bilateral elicitors was measured at 1-, 2-, and 4-kHz signal frequencies using forward masking paradigms at a range of elicitor levels in a repeated measures design. Ipsilateral and bilateral strengths were similar and significantly larger than contralateral strength across signal frequencies. Growth of gain reduction with precursor level tended to differ with signal frequency, although not significantly. Data from previous studies are considered in light of the results of this study. Behavioral results are also considered relative to anatomical and physiological data on the MOCR. These results indicate that, in humans, cochlear gain reduction is broad across frequencies and is robust for ipsilateral and bilateral elicitation but small for contralateral elicitation.
有一些心理声学方法被认为可以测量增益减少，这些方法可能来自内侧橄榄耳蜗反射（MOCR），这是一个双边反馈回路，可以调节耳蜗增益。虽然研究已经使用同侧和对侧激发器，并检查了不同信号频率下的强度，但这些因素在单个研究中尚未得到检验。因此，关于增益减少的基本问题，例如同侧与对侧激发的相对强度以及跨信号频率的相对强度，尚不清楚。在当前的研究中，使用前向掩蔽范式，在重复测量设计中，在一系列激发器水平上，在 1kHz、2kHz 和 4kHz 的信号频率下，测量了同侧、对侧和双侧激发器的增益减少，结果表明，同侧和双侧的强度相似，且显著大于信号频率下的对侧强度。增益减少与前导水平的增长趋势随信号频率而不同，尽管没有显著差异。根据这项研究的结果，考虑了先前研究的数据。还根据 MOCR 的解剖学和生理学数据来考虑行为结果。这些结果表明，在人类中，耳蜗增益减少在频率上很广泛，对于同侧和双侧激发是强大的，但对于对侧激发是较小的。
