Electrophysiological and psychophysical measures of auditory temporal processing

描述（由申请人提供）：该项目的长期目标是确定嘈杂背景下脑干对复杂声音线索反应中明显的时间处理缺陷与言语感知困难之间的关系。提出的研究的具体目的是表征脑干编码的语言和其他复杂的刺激在年轻人和老年人。本实验旨在比较听力接近正常的年轻听众和老年听众，以了解时间处理保真度的降低如何影响语音时间成分的编码，从而影响语音感知。目的1将采用由语音引起的听觉脑干反应测量作为周期性编码的指标。本研究将测试的主要假设，即周期性编码的程度测量的水平

DESCRIPTION (provided by applicant): The long-term aim of this project is to determine the relationship between temporal processing deficits apparent in the brainstem response to complex acoustic cues and speech perception difficulties in noisy backgrounds. The specific objective of the proposed research is to characterize the brainstem encoding of speech and other complex stimuli in young and older adults. The proposed experiments are designed to compare younger and older listeners with near-normal audiometric hearing in order to understand how reduced fidelity of temporal processing affects encoding of the temporal components of speech and, consequently, speech perception. Aim 1 will employ auditory brainstem response measures elicited by speech as an index of periodicity coding. This study will test the primary hypothesis that the degree of periodicity coding measured at the level of the brainstem is dependent on stimulus duration. Aim 2 will model temporal deficits exhibited in the aging auditory system by estimating a measure of 'internal noise' for the older adults. This study will rely on an evaluation of the brainstem response elicited by speech stimuli that has been corrupted using a temporal jitter model. Aim 3 will relate the electrophysiological measures to psychophysical and speech perception measures in young and older adults. Both the psychophysical task (detection of dichotic low-rate frequency modulation) and the speech task (modulation masking release) are designed to capture aspects of temporal processing. The training program involves strong mentorship in research design, especially in the domain of signal processing (stimulus generation, response analysis, etc.) and data analysis essential to the proposed research. Results will contribute to a more refined understanding of sub-cortical processing of speech sounds and the effects of temporal processing deficits on speech processing. The translational emphasis of this project is to optimize the use of complex-ABR measures for the assessment of clinical populations who experience difficulty perceiving speech despite audiometrically normal hearing.