Individual differences in supra-threshold sound encoding

超阈值声音编码的个体差异

基本信息

批准号：
8816966
负责人：
Barbara Shinn-Cunningham
金额：
$ 34.79万
依托单位：
BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-12-01 至 2019-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8816966
关键词：
Acoustic Nerve Affect Animals Attention Audiometry Auditory Auditory Brainstem Responses Brain Stem Clinical Cochlea Code Communication Communication impairment Computer Simulation Cues Detection Diagnosis Exhibits Frequencies Genetic Variation Growth Hearing High-Frequency Hearing Loss Individual Individual Differences Intervention Lead Measures Mechanics Modeling Nerve Fibers Neuropathy Noise Noise-Induced Hearing Loss Normal Range Outcome Perception Performance Peripheral Physiological Psychophysics Role Sensory Source Speech Stimulus Synapses Testing Time Variant Work attentional modulation auditory pathway behavior measurement cohort design encephalography executive function falls hearing impairment insight novel otoacoustic emission public health relevance remediation research clinical testing response selective attention social sound

项目摘要

DESCRIPTION (provided by applicant): A long-standing puzzle is why listeners with normal hearing thresholds show such enormous variation in performance on other auditory tasks. Differences among "normal hearing" listeners are particularly pronounced when tasks involve separating multiple sound sources, such as when listeners must rely on selective auditory attention. Recent animal work shows that noise exposure can damage the synaptic efficacy of auditory nerve fibers without permanently altering hearing thresholds, producing auditory neuropathy. Low-spontaneous rate auditory nerve fibers, which are especially important for encoding the temporal content of supra-threshold sound, may be preferentially affected. Consistent with animal studies, our preliminary results in listeners with normal thresholds suggest that inter-subject performance differences on selective attention tasks correlate with psychophysical and physiological measures designed to reveal the fidelity of temporal coding at supra-threshold levels. We hypothesize that auditory neuropathy may be much more common than previously recognized: young listeners with normal hearing thresholds may differ in the fidelity with which their auditory nerve fibers encode supra-threshold temporal information, affecting their ability to communicate in everyday settings. Sound exposure leads to supra-threshold deficits in animals without threshold shifts; thus, we also postulate that listeners with conventionally defined hearing loss from noise exposure likely also suffer from supra-threshold deficits that contribute substantially to communication difficulties. The main objective of this project is to quantify auditory neuropathy in a cohort of young, "normal hearing" listeners. We will also explore how supra-threshold encoding contributes to performance differences in listeners with elevated thresholds due to noise exposure. We will: Aim 1) characterize individual differences in supra-threshold sound encoding in subcortical portions of the auditory pathway; Aim 2) characterize individual differences in the ability to selectively attend, and relate them to differences in coding fidelity; and Aim 3) characterize how supra-threshold sound encoding fidelity contributes to performance differences for listeners with mild to moderate high-frequency hearing loss. We will compare physiological (brainstem responses, distortion product otoacoustic emissions, and cortical responses) and behavioral measures from the same listeners and use computational models to unravel the relationships between these metrics. Our results will quantify how peripheral encoding of supra-threshold sound differs across listeners with both normal and elevated thresholds, and will establish how supra-threshold differences affect the ability to communication in common social settings. Our results could lead to a clinical test of supra-threshold hearing fidelity, quantifying one factor leading to differences in communication ability amongst listeners with similar audiograms.

描述（由申请人提供）：一个长期的难题是为什么具有正常听力阈值的听众表现出其他听觉任务上表现的巨大变化的原因。当任务涉及分开多个声源时，例如听众必须依靠选择性的听觉关注时，“正常听力”听众之间的差异特别明显。最近的动物工作表明，噪声暴露会损害听觉神经纤维的突触功效，而不会永久改变听力阈值，从而产生听觉神经病。低自发率的听觉神经纤维可能会受到优先影响，这对于编码上阈值的时间含量尤其重要。与动物研究一致，我们的初步结果在阈值正常的听众中表明，选择性注意任务的受试者间绩效差异与旨在揭示上超阈值水平上时间编码的忠诚度相关的心理物理和生理措施。我们假设听觉神经病可能比以前所认识的更为普遍：具有正常听力阈值的年轻听众可能会在听觉神经纤维编码上阈值的时间信息上的忠诚度有所不同，从而影响他们在日常环境中交流的能力。声音暴露会导致阈值上阈值不足，没有阈值移动；因此，我们还假设听众与传统上定义的噪声暴露的听力损失也可能遭受上阈值上的赤字，这对沟通困难产生了重大贡献。该项目的主要目的是在一系列年轻的“正常听力”听众中量化听觉神经病。我们还将探讨超阈值编码如何导致由于噪声暴露而导致阈值升高的听众的性能差异。我们将：AIM 1）表征在听觉途径的下皮层中编码上阈值阈值的个体差异；目标2）特征在于选择性地参加的能力的个体差异，并将其与编码保真度的差异； AIM 3）表征超阈值编码忠诚度如何促进轻度至中度高频听力损失的听众的性能差异。我们将比较生理学（脑干反应，失真产物耳声排放和皮质反应）和来自相同听众的行为度量，并使用计算模型来揭示这些指标之间的关系。我们的结果将量化阈值阈值的外围编码如何在正常和阈值升高的听众中差异，并将确定超阈值差异如何影响共同社交环境中的交流能力。我们的结果可能导致临床阈值上听力忠诚度的测试，量化一个因素，从而导致听力图相似的听众之间的沟通能力差异。