Observing auditory mechanics with pressure and motion measurements

描述（由申请人提供）：用压力和运动测量探索听觉力学。本文提出的一系列实验利用我们实验室开发的压力传感器和其他特殊技术，辅以激光多普勒测速等成熟方法，探索听觉力学。前四个目标的项目继续并扩展了我们之前在内耳和中耳力学方面的工作。最终目的是开发和评价一种新的人工耳蜗植入方法。声音输入引起内耳内感觉组织运动的波状模式，该波状模式被传递到听神经，导致听力。这发生在实验可及性非常有限的耳蜗腔内。这里提出的第一和第二项研究目标将用专门的微型传感器推进这些难以接近的隔间。目标一使用进一步小型化的微压力传感器在体内测量scala介质压力。目的二是将我们实验室已经建立的鼓室压力测量与耳蜗麦克风测量相结合，在Corti器官的微米范围内进行测量。这两个目标都是为了检验具体的理论预测，以便对知识的进步产生强烈的影响。即使在鼓膜对声音有复杂的随机波响应的频率下，声音也能通过中耳以高保真度传输。最近的理论采用鼓膜波进行声音传播，我们的目标是通过用硬化剂改变波速来预测，用激光测速仪测量波速，以及用耳蜗内压力监测声音传播。我们的第二个中耳目标探讨了一个理论预测，即鼓膜后面的空气腔提供反射，这是高频良好声音传输的基础。最后，我们的最后一个目的是探索一种利用粘性力插入深度人工耳蜗的新方法。该方法将在拟议的研究中进行生理学评估。

DESCRIPTION (provided by applicant): Exploring Auditory Mechanics with Pressure and Motion Measurements. The series of experiments proposed here use pressure sensors and other special techniques developed in our lab, complemented by well-established methods like laser-doppler velocimetry, to explore auditory mechanics. The projects of the first four aims continue and extend our previous work on inner and middle ear mechanics. The final aim develops and evaluates a new method for deep cochlear implant insertion. Sound input causes a wave-pattern of sensory tissue motion within the inner ear that is conveyed to the auditory nerve, leading to hearing. This takes place within cochlear compartments having very limited experimental accessibility. Aims one and two of the studies proposed here will push into these barely accessible compartments with specialized micro-sensors. Aim one uses a further miniaturized micro-pressure sensor for in vivo measurements of scala media pressure. Aim two advances our lab's well- established scala tympani pressure measurements by combining them with cochlear microphonic measurements at the same location, within micrometers of the organ of Corti. Both aims are designed to test specific theoretical predictions in order to have a strong impact on the advancement of knowledge. Sound is transmitted by the middle ear with high fidelity even at frequencies where the eardrum has a complex, random-wavy response to sound. Recent theories employ the eardrum wave for sound transmission, and our aim three tests that prediction by changing the wave speed with stiffening agents, measuring the wave speed with a laser velocimeter and also monitoring sound transmission with intracochlear pressure. Our second middle ear aim explores a theoretical prediction that the air cavity behind the eardrum provides reflection that is the basis for good sound transmission at high frequencies. Finally, our last aim explores a novel method for deep cochlear implant insertion using viscous forces. The method will by evaluated physiologically in the proposed studies. PUBLIC HEALTH RELEVANCE: Exploring auditory mechanics with pressure and motion measurements. The core objective of the project is to understand the mechanical processing of the auditory periphery: how the middle ear effectively transmits sound to the inner ear, and the mechanical processing that leads to a frequency-sorted pattern of vibration along the long narrow strip of sensory tissue in the inner ear. Additionally, we have developed a non-traumatic method of cochlear implant insertion and will further develop and test this method. We use micro-pressure-sensors that were developed in our laboratory, and laser-based methods for measuring tiny motions, in order to test current theories of the operation of the ear and measure mechanical responses in implanted inner ears.