COCHLEAR MECHANISMS OF FREQUENCY MICROSTRUCTURE

该方案中的实验旨在研究 听阈和耳声的频率微结构 (OAE)现象。频率微结构的临床意义 将通过检查患有耳蜗病的耳朵来探索。这个 这一研究的最终目标将是开发出更具体的 诊断耳声发射程序。该建议的具体问题如下： 1)频率微结构的耳蜗机制是两者共同的吗 听阈值和刺激频率？直接 Threshold和SFOAE的微观结构比较 相同的正常耳朵(根据最大/最小频率和幅度 远足)将被用来评估和对比几个对立的 关于潜在耳蜗机制的假说。2)是频率 失真产物耳声发射的微观结构 与多个产生源有关的频率函数？比较 用几种不同的基波测量的DPOAE频率函数 相互之间的刺激方案和具有听觉阈值的方案将 用于比较两种理论(Allen和Faey，1993；Stover， Neely和Gorga；，1997)3)经验结果是否可以复制，以及 假说在人工耳蜗术数学模型中的实现 机械师？将尝试将随机波动纳入 耳蜗区划分的几个方面的数学模型 Cochlea(Neely，1993)，它将复制经验数据，同时允许 模型保持稳定。4)频率微结构的损失 在没有听力损失的情况下发生衰老吗？频率微结构 在正常听力和轻度听力损失范围内进行比较 两个年龄段的成年人在听力阈值上仔细匹配。 5)DPOAE频率微结构能解释DPOAE频率微结构的缺失吗 DPOAEs在临床诊断中的特异性？基于之前的数据 实验一个DPOAE频率函数的简化协议将是 对听力正常至轻度的大量受试者进行评估 听力损失试图改善听力的临床评估 临界点。

The experiments in this proposal are designed to investigate the frequency microstructure of both auditory thresholds and otoacoustic (OAE) phenomena. The clinical ramifications of frequency microstructure will be explored by examining ears with cochlear impairment. The ultimate goal of this line of research will be to develop more specific diagnostic OAE procedure. The specific questions of the proposal are: 1) Is the cochlear mechanism for frequency microstructure common to both auditory threshold and stimulus frequency OAEs (SFOAEs)? Direct comparison of the microstructure of both threshold and SFOAE from the same normal ears (in terms of frequencies of maxima/minima and amplitude excursion) will be used to evaluate and contrast several opposing hypotheses regarding underlying cochlear mechanisms. 2) Is frequency microstructure in distortion product otoacoustic emissions (DPOAE) frequency functions related to multiple generation sources? Comparison of DPOAE frequency functions as measured with several different primary stimulus protocols among each other and with auditory thresholds will be used to compare between two theories (Allen and Fahey, 1993; Stover, Neely and Gorga;, 1997) 3) Can empirical results be reproduced by, and the hypothesis implemented in a mathematical model of cochlear mechanics? Attempts will be made to incorporate random fluctuations in several aspects of the cochlear partition in a mathematical model of the cochlea (Neely, 1993) which will reproduce empirical data while allowing the model to remain stable. 4) Does loss of frequency microstructure occur in aging in the absence of hearing loss? Frequency microstructure across normal hearing and mild hearing loss ranges will be compared for two age groups of adults carefully matched for audiometric threshold. 5) Can DPOAE frequency microstructure account for the lack of specificity of DPOAEs in clinical diagnostics? Based on earlier experiments a shortened protocol of DPOAE frequency functions will be evaluated on a large population of subjects with normal hearing to mild hearing losses in an attempt to improve clinical estimation of auditory threshold.