Experimental study of the cochlear amplifier

人工耳蜗放大器的实验研究

• 批准号: 6436899
• 负责人: TIANYING REN
• 金额: $ 26.07万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-28 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6436899
• 关键词: auditory discrimination; auditory feedback; auditory stimulus; behavioral /social science research tag; biological models; biomechanics; cochlea; cochlear microphonic potentials; ear hair cell; electrical property; electrophysiology; electrostimulus; gerbil /jird; heterodyning; microelectrodes; model design /development; otoacoustic emission; physical model; psychoacoustics; statistics /biometry; video recording system

DESCRIPTION (provided by applicant) As a hydromechanical frequency analyzer of complex environmental sounds, the mammalian cochlea is capable of processing amplitude, phase, and frequency-varying sounds in a wide dynamic range and with a high degree of frequency and time resolution. These capabilities are due to the remarkable sensitivity, nonlinearity, and sharp tuning of the cochlea. To understand how the cochlea works, a cochlear amplifier (CA) has been proposed by some investigators, which amplifies the basilar membrane (BM) vibration evoked ! by low level sound and enhances mechanical frequency selectivity. The CA is proposed to work by obtaining energy from the outer hair cells (OHCs) on a cycle-by-cycle basis, resulting in enhancement or suppression of the BM vibration through either positive or negative feedback, depending on frequency. The aim of this study is to experimentally test if the CA exists through the use of our newly developed signal processing method and to study the feedback hypothesis of the CA by observing the phase relationships of the BM vibrations evoked by acoustical and electrical stimuli. The following specific aims will be investigated: i) whether the long delay component (LDC) of the EEOAE comes from the characteristic frequency place on the BM, ii) whether the amount of LDC acoustical energy changes with cochlear sensitivity, and iii) whether the CA gain is numerically greater than one and whether it is dependent on the level of electrical current or the EEOAE sound pressure. Finally, iv) the amplitude and phase of the BM velocity evoked by acoustical and electrical stimuli will be measured as functions of frequency and intensity. The phase relationship beneath the OHCs will be used to test the frequency and level dependent feedback mechanism of the CA. Because of the noninvasive approach, the wide frequency response feature of the EEOAE, and the inherent self-testing property of the method, the gain measurement of the CA in this proposed study is expected to be accurate and reliable. The project provides fundamental experimental data both for advancing our understanding of cochlear mechanisms and for using multiple component analysis method as an important tool for auditory research and clinical diagnosis.

描述（由申请人提供） 作为流体力学频率分析仪 哺乳动物的耳蜗能够处理复杂的环境声音 宽动态范围内的振幅、相位和频率变化的声音 高度的频率和时间分辨率。这些能力是由于 耳蜗卓越的灵敏度、非线性和敏锐的调谐能力。到 了解耳蜗的工作原理，提出了耳蜗放大器 (CA) 一些研究人员认为，这会放大基底膜（BM）振动 诱发！通过低电平声音并增强机械频率选择性。这 CA 的工作原理是从外毛细胞 (OHC) 获取能量 逐个周期的基础上，导致 BM 的增强或抑制 通过正反馈或负反馈振动，具体取决于频率。 本研究的目的是通过实验测试 CA 是否存在 使用我们新开发的信号处理方法并研究反馈 通过观察 BM 振动的相位关系来提出 CA 假设 由声和电刺激引起。将实现以下具体目标 被调查： i) EEOAE 的长延迟分量 (LDC) 是否来自 BM上的特征频率位置，ii)是否有LDC量 声能随耳蜗灵敏度的变化而变化，以及 iii) CA 是否 增益在数值上大于 1，是否取决于级别 电流或 EEOAE 声压。最后，iv) 振幅 声学和电刺激引起的 BM 速度的相位将 作为频率和强度的函数来测量。相位关系 OHC 下方将用于测试频率和电平相关的 CA的反馈机制。由于采用非侵入性方法，广泛 EEOAE的频率响应特性以及固有的自测试特性 根据该方法，本研究中 CA 的增益测量为 预计准确可靠。该项目提供了基础 实验数据都有助于增进我们对耳蜗机制的理解 并使用多组分分析方法作为重要工具 听觉研究和临床诊断。