COCHLEAR MECHANICS, WAVE PROPAGATION, AND COMPRESSION

描述(由申请者提供)：本研究计划专注于理论和实证研究，解决当前耳蜗力学中与非侵入性评估耳蜗功能相关的问题。这些研究的主要目的是了解耳蜗波的传播和表征耳蜗波的压缩。这些目标是通过六个具体目标来实现的。前三个目标集中在耳蜗波传播的各个方面，通过针对以下理论问题的建模工作：(1)适当地表征耳蜗放大器的增益；(2)更全面地理解失真产物逆行波的传播；以及(3)了解基底膜测量中凹口的机制。接下来的三个目标是通过涉及人类受试者的经验研究和涉及耳蜗力学模型的理论工作相结合的方式来表征耳蜗压的增长。具体地说，这三项研究旨在增加我们对以下之间关系的理解：(4)压缩增长率(CGR)和前向掩蔽心理测量函数的斜率；(5)CGR和抑制增长率；(6)CGR和耳蜗反射率。建模工作将有助于对测量结果的解释，并提供对耳蜗波传播、耳蜗压和负阻尼区的更深层次理解。可靠的CGR估计对于听力损失的修复具有重要的临床意义，因为它与正常值的偏差提供了外部助听器需要提供的压力量的准确估计。这项拟议的研究的目标是开发一种耳蜗力学的计算模型，该模型将有助于解释人类外周听觉状态的非侵入性测量。这项工作与公共健康有关，因为听力损失的人不仅有听不到柔和声音的问题，他们还会感受到声音增长太快。了解听力感觉器官(耳蜗)如何影响响度的增长，应该为设计适合个人需求的助听器提供有用的信息。

DESCRIPTION (provided by applicant): This research program focuses on theoretical and empirical studies that address current issues in cochlear mechanics relevant to noninvasive evaluation of cochlear function. The major objectives of these studies are to understand cochlear-wave propagation and to characterize cochlear compression. These objectives are approached through six specific aims. The first three aims focus on aspects of cochlear-wave propagation through modeling efforts directed at the following theoretical issues: (1) appropriate characterization of cochlear-amplifier gain; (2) a more complete understanding of distortion-product retrograde wave propagation; and (3) understanding the mechanisms that underlie notches in basilar-membrane measurements. The next three aims characterize cochlear compression growth through a combination of empirical studies involving human subjects and theoretical work involving models of cochlear mechanics. Specifically, these three studies are designed to increase our understanding of the relation between: (4) compression growth rate (CGR) and the slope of forward-masking psychometric functions; (5) CGR and suppression growth rate; and (6) CGR and cochlear reflectance. The modeling work will facilitate interpretation of the measurements and provide a deeper understanding of cochlear wave-propagation, cochlear compression, and negative damping regions. Reliable estimation of CGR is clinically significant for the remediation of hearing loss because its deviation from normal provides a precise estimate of the amount of compression that an external hearing aid needs to provide. The goal of the proposed research is the development of a computational model of cochlear mechanics that will facilitate the interpretation of noninvasive measures of peripheral auditory status in humans. This work is relevant to public-health because people with hearing loss not only have problems hearing soft sounds, they also experience sounds growing louder too quickly. Understanding how the sense organ of hearing (the cochlea) influences the growth of loudness should provide useful information for the design of hearing aids tailored to individual needs.