Level encoding in the AN and CN of hearing-impaired

描述（由申请人提供）：拟定的神经生理学实验 由声级编码的两个基本方面激发， 严重受耳蜗损伤的影响，目前提供了重要的 设计有效助听器的挑战。(1)响度重振 表示存在的降低的动态范围和异常响度增长， 几乎所有听力受损的人都有耳蜗损伤。人们通常认为 响度与由声音引起的总神经活动有关; 然而，这种关系的性质在正常和受损中仍不清楚。 耳朵目的之一是系统地描述神经活动的增长 随着刺激水平的增加，神经纤维（AN）的数量增加， 正常和听力受损的猫。刺激是基于典型的心理物理 测量响度补充的研究，包括音调，宽带噪声， 言语和面具的音调。(2)复杂声信号的鲁棒谱形编码 刺激是许多基本听觉功能所必需的， 通信语音表示的显著增强 据报道，在从AN到耳蜗核（CN）的转化中， 听力正常的动物第二个目的是比较频谱形状编码， 正常猫和听力受损猫的CN。将使用两种方法来 评估用于编码光谱形状的相对水平灵敏度， 腹侧CN的不同细胞类型。收集的数据将改善 了解耳蜗损伤如何影响声音的神经表征， 并将为设计新的助听器策略提供有用的信息 为了克服响度恢复，同时维持和增强频谱特性， 表示.

DESCRIPTION (provided by applicant): The proposed neurophysiological experiments are motivated by two fundamental aspects of sound-level encoding that are strongly affected by cochlear damage and that currently provide significant challenges for the design of effective hearing aids. (1) Loudness recruitment represents the reduced dynamic range and abnormal loudness growth present in almost all hearing-impaired persons with cochlear damage. It is often assumed that loudness is related to the total neural activity evoked by a sound; however, the nature of this relation remains unclear in normal and impaired ears. One aim is to systematically characterize the growth of neural activity with increasing stimulus level in a population of auditory-nerve (AN) fibers for normal and hearing-impaired cats. Stimuli are based on typical psychophysical studies that measure loudness recruitment, and include tones, broadband noise, speech, and masked tones. (2) Robust spectral-shape encoding of complex acoustic stimuli is necessary for many basic auditory functions that underlie communication. A significant enhancement in the representation of speech has been reported in the transformation from the AN to the cochlear nucleus (CN) in normal-hearing animals. The second aim is to compare spectral-shape encoding in the CN of normal and hearing- impaired cats. Two methods will be used to evaluate the relative-level sensitivity for encoding spectral shape in the different cell types of the ventral CN. The data collected will improve the understanding of how cochlear damage affects the neural representation of sound, and will provide useful information for the design of new hearing-aid strategies to overcome loudness recruitment while maintaining and enhancing spectral representation.