Backward and Forward Driven Eardrum Motions

描述（由申请人提供）：声音引起的鼓膜（TM）位移是环境声音到耳蜗内声音的正向转换的第一阶段，而听骨链的机械运动引起的TM位移是耳蜗产生的声音到耳道中测量的临床上有价值的耳声发射（OAE）的反向转换的最后阶段。然而，我们对TM在正向和反向声音传输中的工作原理的了解是有限的。虽然最近的研究表明，复杂的TM表面运动响应耳道声音在高频率是一致的多波共存的TM表面上，不同的TM位移波的贡献，激发听骨链和随后的声音传输到内耳还不清楚。此外，TM如何响应由内耳产生的声音或听小骨的机械刺激产生的听小骨运动的知之甚少。也有一个缺乏的数据描述的空间声压分布附近和远离TM，即使它是已知的，有显着的非均匀性TM运动在正向和反向的声音传输。本研究旨在：（1）响应于由耳道内产生的声音的正向刺激和由有源中耳植入物产生的反向机械刺激来表征TM表面运动;（2）产生TM附近和远离TM的声压的详细空间分布，其将与正向和反向刺激中的详细TM表面运动相关;（3）量化（a）TM表面运动和通过中耳到耳蜗激励的声能传输与（B）听骨运动和反向刺激中TM的声音转换之间的关系。我们采用一种新开发的频闪全息干涉仪测量位移振幅和相位响应于不同的刺激在TM表面上超过30万个点，连同一个计算机控制的麦克风定位系统，系统地采样的声压在耳道内的近（1毫米内）和远（最多10毫米）从TM表面。实现这些目标将：（i）量化由正向和反向刺激产生的TM表面运动的不同波类型、波幅和波长;（ii）更好地确定不同TM表面波对两个方向上的声音传输的贡献;（iii）更好地描述TM在临床上有用的耳声发射测量中的作用;和（iv）研究后向驱动耳道声压测量在评价驱动完整听骨链或圆窗的主动中耳假体中的临床效用。

DESCRIPTION (provided by applicant): Sound-induced displacement of the Tympanic Membrane (TM) is the first stage in the forward transformation of environmental sound to sound within the cochlea, while displacement of the TM induced by mechanical motions of the ossicular chain is the last stage in the reverse transformation of cochlea generated sound to clinically valuable oto-acoustic emissions (OAEs) measured in the ear canal. However, our knowledge of the workings of the TM in both forward and reverse sound transmissions is limited. Although recent studies suggest complex TM surface motions in response to ear-canal sound at high frequency are consistent with multiple waves co-existing on the TM surface, the contributions of different TM displacement waves to excitation of the ossicular chain and subsequent sound transmission to inner ear are unclear. Furthermore, little is known of how the TM responds to ossicular motions produced by inner-ear generated sound or mechanical stimulation of the ossicles. There is also a lack of data describing spatial sound-pressure distributions near and far from the TM even though it is known that there are significant non-uniformities in TM motion in both forward and reverse sound transmission. This study aims to: (1) Characterize TM surface motions in response to forward stimulation by sound generated within the ear canal and reverse mechanical stimulation produced by an active middle-ear implant; (2) Produce detailed spatial profiles of sound pressure near and far from the TM that will be correlated with detailed TM surface motions in forward and reverse stimulation; and (3) Quantify the relationship between (a) TM surface motions and sound energy transmission through the middle ear to the cochlear excitations and (b) Ossicular motion and the sound transformation by the TM in reverse stimulation. We employ a newly developed stroboscopic holographic interferometer to measure displacement amplitude and phase in response to different stimuli at over 300000 points on the TM surface, together with a computer-controlled microphone positioning system to systematically sample the sound pressure within the ear canal both near (within 1 mm) and far (up to 10 mm) from the TM surface. Accomplishing these aims will: (i) Quantify the different wave types, wave amplitude and wavelength of TM surface motions produced by forward and reverse stimulation; (ii) Better define the contributions of different TM surface waves to sound transmissions in both directions; (iii) Better describe the action of the TM in clinically useful oto-acoustic emission measurements; and (iv) Investigate the clinical utility of backward driven ear-canal sound pressure measurements in the evaluation of active middle-ear prostheses that drive the intact ossicular chain or the round window.