HUMAN MIDDLE EAR--FORWARD AND REVERSE SOUND TRANSMISSION

这个项目试图描述向前和向后的声音 通过人类中耳传播。其中最 在过去的二十年里，听力方面的重大发现 因为健康的耳朵不仅能探测到声音，还能产生 听起来。这种“反向能量流”起源于耳蜗部， 通过中耳传播，可作为耳声测量 耳道中的排泄物。耳声的可及性 排放到测量使它们成为一个潜在有用的工具 目的评价耳蜗术后患者的耳功能和中耳功能。然而， 人们对中耳对耳声的影响知之甚少。 排放物，因此我们对内耳的看法被 对中耳的不完全了解。为了理解如何 中耳影响向前和向后的声音传播， 将在具体修改之前和之后进行测量 到人类身体的中耳。衡量标准将包括 从耳道到内耳的中耳压力增加 (前向压力增加)，中耳从内部获得压力增加 耳对耳道(反向压力增加)，中耳输入 阻抗和耳道压力-速度传递。 中耳改良的例子包括距骨固定术。 (如耳硬化症)，砧头-锤头固定，以及 鼓膜穿孔。这些测量将被用来开发 正常人和正常人中耳的数学模型 病理情况。为了测试 正常和病理活体对象的数学模型 中耳、气磨间隙和耳声发射 在人类受试者身上测量。对受试者的测量将是 与数学模型的结果进行了比较。这些比较 都是为了测试数学模型的适用性 给活着的人类，并允许我们想出方法来移除 测量结果对中耳的混杂影响 并因此增加耳声发射的一般用途 耳声发射在耳蜗术前诊断中的应用 功能障碍。

This project seeks to characterize forward and reverse sound transmission through the human middle ear. One of the most significant discoveries in hearing during the past twenty years has been that a healthy ear not only detects sound but also generates sounds. This "reverse energy flow" originates in the cochlea, travels through the middle ear and can be measured as otoacoustic emissions in the ear canal. The accessibility of otoacoustic emissions to measurements makes them a potentially useful tool for objective evaluation of cochlear and middle-ear function. However, little is known about the effect of the middle ear on otoacoustic emissions and thus our view of the inner ear is clouded by incomplete knowledge of the middle ear. To understand how the middle ear affects forward and reverse sound transmission, measurements will be made before and after specific modifications to the middle ears of human cadavers. Measurements will include middle-ear pressure gain from the ear canal to the inner ear (forward pressure gain), middle-ear pressure gain from the inner ear to the ear canal (reverse pressure gain), middle-ear input impedance, and ear-canal pressure to stapes-velocity transmission. Examples of middle-ear modifications include fixation of the stapes (as in otosclerosis), fixation of the incus-malleus head, and eardrum perforations. These measurements will be used to develop mathematical models of the human middle ear for normal and pathological conditions. To test the applicability of the mathematical models to living subjects with normal and pathological middle ears, air-hone gap and otoacoustic emissions will be measured in human subjects. Measurements on subjects will be compared with results of the mathematical models. These comparisons are intended to test the applicability of the mathematical models to living humans and to allow us to devise ways to remove the confounding effects of the middle ear from measurements of otoacoustic emissions and thus increase the general utility of otoacoustic emissions as a diagnostic tool for detecting cochlear dysfunction.