CLINICAL MEASURES OF AUDITORY LINEAR/NONLINEAR PROCESSES

临床听力学的一个常见发现是， 听力损失程度相似的人 在言语感知的测量上不同。 因此，这些人 从放大中获得的好处可能有所不同。 一个原因 因为听力受损的听众之间缺乏同质性， 听力图仅提供耳蜗病理的粗略估计。 因此 有可能听力受损的听众在他们的潜在的 耳蜗病理学和纯音听阈的测量缺乏 敏感度来区分这些个体。 耳蜗病理改变耳蜗转导过程。 机械- 电和机电转换过程被修改，或者 直接通过毛细胞结构的变化，或间接通过 毛细胞转导所依赖的结构。 的客观测量 描述这些过程的特征将描述 耳蜗疾病的后果，并提供更准确的描述 感音神经性听力损失 临床 耳蜗传导的测量可能会导致一个新的分类方案 感音神经性听力损失的基础上潜在的病理生理学。 本研究的长期目标是使用这种方案来确定 如果耳蜗的潜在生理变化可以解释 听力受损的听众之间的变化对功能的措施， 助听器是一种新型的助听器。 相干信号转导过程本质上是非线性的，因此， 耳蜗传导的测量必须对非线性过程敏感。 听觉失真产物是非线性的指标，反映了听觉系统的非线性特征。 耳蜗的完整性，但他们的缺席只表明了一个变化， 转导，而不是对改变的转导过程的描述。 一 Bendat（1990）提出的一种新的非线性系统辨识方法 可用于表征耳蜗转导过程， 频率范围。 该技术可应用于ECochG、AEP和 耳声发射，因此，机电和机电转换 可以描述耳蜗中的过程。 这个特别的目标 调查是使用Bendat的程序来制定一个衡量标准， 耳蜗传导，量化测量的可靠性，以及 确定其对耳蜗生理学变化的敏感性， 耳蜗损伤

A common finding in clinical audiology is that hearing-impaired listeners with similar configurations and degrees of hearing loss perform differently on measures of speech perception. Consequently, these people may differ in the benefits they receive from amplification. One reason for the lack of homogeneity among hearing-impaired listener is that the audiogram provides only a rough estimate of cochlear pathology. Thus, it is possible that hearing-impaired listeners differ in their underlying cochlear pathology and measures of pure-tone threshold lack the sensitivity to distinguish these individuals. Cochlear pathology alters cochlear transduction processes. Mechano- electric and electro-mechanic transduction processes are modified, either directly through changes in hair cell structure, or indirectly, through structures on which hair cell transduction relies. An objective measure that characterizes these processes will describe the physiologic consequences of cochlear disorders and supply a more accurate description of sensorineural hearing loss then presently available. A clinical measure of cochlear transduction could lead to a new categorization scheme of sensorineural hearing loss based on the underlying pathophysiology. The long term goal of this research is to use such a scheme to determine if the underlying physiologic changes in the cochlea can account for the variation between hearing-impaired listeners on functional measures of hearing, and design new signal processing algorithms for hearing aids. Cochlear transduction processes are inherently nonlinear, therefore, a measure of cochlear transduction must be sensitive to nonlinear processes. Auditory distortion products are indices of nonlinearity and reflect cochlear integrity, but their absence only indicates a change in transduction, not a description of the altered transduction processes. A new nonlinear systems identification procedure developed by Bendat (1990) can be used to characterize cochlear transduction processes across a broad range of frequencies. This technique can be applied to ECochG, AEPs, and OAEs, thus, both mechano-electric and electro-mechanic transduction processes in the cochlea can be described. The special goal of this investigation is to use Bendat's procedure to develop a measure of cochlear transduction, quantify the reliability of the measure, and determine its sensitivity to changes in cochlear physiology due to cochlear damage.