Cochlear micromechanical mechanisms underlying psychoacoustic phenomena

心理声学现象背后的耳蜗微机械机制

• 批准号: 10715565
• 负责人: TIANYING REN
• 金额: $ 58.05万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-16 至 2028-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10715565
• 关键词: Acoustic Nerve; Action Potentials; Affect; Apical; Basilar Membrane; Clinic; Cochlea; Complex; Detection; Diagnosis; Frequencies; Gerbils; Hearing problem; Human; Inner Hair Cells; Knowledge; Location; Measurement; Measures; Mechanics; Music; Nerve Fibers; Noise; Outer Hair Cells; Patients; Pitch Perception; Procedures; Psychoacoustics; Psychophysics; Role; Scientist; Series; Speech; Stimulus; Testing; cell motility; experimental study; fascinate; hearing impairment; improved; neural; novel; response; sound; vibration

Project Summary/Abstract Although the pitch of missing fundamentals has been studied for more than a century, and psychophysical tuning curves and gap detection have been used as non-invasive tests for diagnosing auditory disorders, the cochlear mechanical mechanisms underlying these psychoacoustic phenomena remain unclear. This project aims to study the cochlear micromechanical mechanisms contributing to the pitch of missing fundamentals, psychophysical tuning curves, and gap detection by measuring the reticular lamina (RL) vibration from apical ends of the outer hair cells (OHCs) and the auditory nerve potential in living gerbil cochleae. Our overarching hypothesis is that the mechanical missing fundamental is generated by OHCs and can be detected at the cochlear locations tuned to stimulus frequencies. Masker-induced suppression and enhancement and poststimulation oscillation of the RL vibration contribute to the neural tuning curves and gap detection. This hypothesis will be tested by conducting the following experiments. Experiment One will measure the cochlea- generated fundamentals in the RL vibration and auditory nerve potential and observe the effect of a noise masker on the RL and auditory nerve fundamentals. The unmaskable RL and auditory nerve fundamentals will indicate that the cochlea can generate the fundamental, and this cochlea-generated fundamental can be detected at cochlear locations tuned to stimulus frequencies. Experiment Two will measure the RL mechanical tuning curves, the auditory nerve simultaneous and forward masking tuning curves, and the masker-induced changes in the RL probe response. The results from this experiment will determine whether the simultaneous or forward masking tuning curve can accurately reflect the RL mechanical tuning curve and whether the masker-induced changes in the RL probe response contribute to the cochlear compound action potential (CAP) tuning curves. Experiment Three will measure the RL poststimulation vibration and compare the duration of this persistent vibration to the gap detection threshold. The expected result from this experiment will indicate that the RL poststimulation can excite the inner hair cells and auditory nerve fibers during the gap period, which affects the auditory nerve response to the stimulus after the gap. Thus, the results from this study will reveal cochlear micromechanical mechanisms underlying the pitch of missing fundamentals, psychoacoustic tuning curves, and gap detection. The knowledge gained from this project can benefit patients by optimizing procedures and improving the interpretation of psychoacoustic tests in clinics.

项目总结/摘要 虽然缺失基本音的音高已经被研究了世纪， 调谐曲线和间隙检测已经被用作诊断听觉障碍的非侵入性测试， 这些心理声学现象背后的耳蜗机械机制仍不清楚。这个项目 旨在研究耳蜗微机械机制，有助于音调缺失的基本原理， 心理物理调谐曲线，和间隙检测通过测量网状层（RL）的振动，从顶端 本文报道了沙土鼠耳蜗外毛细胞（OHCs）末梢的电生理和听神经电位的变化。我们的总体 一个假设是，机械丢失的基本面是由OHC产生的，并且可以在 耳蜗位置调整到刺激频率。掩蔽剂诱导的抑制和增强， RL振动的后刺激振荡有助于神经调谐曲线和间隙检测。这 将通过进行以下实验来检验假设。实验一将测量耳蜗- 产生RL振动和听觉神经电位的基本原理，并观察噪声的影响 在RL和听觉神经基础上的掩蔽。无法屏蔽的RL和听觉神经基础将 表明耳蜗可以产生基波，并且这种耳蜗产生的基波可以是 在耳蜗位置被调谐到刺激频率时检测到。实验二将测量RL机械 调谐曲线、听神经同时掩蔽调谐曲线和前掩蔽调谐曲线，以及掩蔽诱导的 RL探针响应的变化。这个实验的结果将决定 或前向掩蔽调谐曲线可以准确地反映RL机械调谐曲线， 掩蔽物引起的RL探针反应的变化有助于耳蜗复合动作电位 (CAP)调谐曲线实验三将测量RL刺激后振动并比较 该持续振动的持续时间与差距检测阈值相比较。这个实验的预期结果将 表明RL后刺激可在差距内兴奋内毛细胞和听神经纤维 期间，这影响了差距后的听觉神经对刺激的反应。因此，由此产生的结果 这项研究将揭示耳蜗的微观机械机制，这些机制是缺失的基本原理的基础， 心理声学调谐曲线和间隙检测。从这个项目中获得的知识可以使病人受益 通过优化程序和改善临床心理声学测试的解释。