Neural measures of temporal processing deficits affecting speech comprehension in listeners with normal hearing thresholds

时间处理缺陷的神经测量影响听力阈值正常的听众的言语理解

• 批准号: 10020167
• 负责人: Mishaela T DiNino
• 金额: $ 4.06万
• 依托单位: CARNEGIE-MELLON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2021-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10020167
• 关键词: Acoustic Nerve; Acoustics; Adult; Affect; Animal Experimentation; Animal Model; Area; Attention; Attenuated; Auditory; Auditory Perception; Auditory Threshold; Behavioral; Brain; Cell physiology; Characteristics; Cochlea; Code; Communication; Communication impairment; Comprehension; Consensus; Cues; Diagnostic tests; Discrimination; Electroencephalography; Environment; Exhibits; Exposure to; Frequencies; Goals; Grouping; Hair Cells; Hearing; Human; Impairment; Individual; Investigation; Knowledge; Lead; Link; Measures; Mechanics; Mentors; Methods; Nerve Fibers; Noise; Participant; Pattern; Perception; Performance; Phase; Physiological; Population; Process; Psychophysics; Quality of life; Research; Scientist; Signal Transduction; Speech; Speech Sound; Stimulus; Stream; Sum; Symptoms; Synapses; Training; Variant; Voice; Work; Workplace; attentional control; attentional modulation; auditory processing; auditory stimulus; career; cochlear synaptopathy; comprehension deficit; experience; experimental study; hearing impairment; noise perception; normal hearing; novel; relating to nervous system; response; segregation; selective attention; signal processing; social; sound; speech in noise; standard measure

PROJECT SUMMARY/ABSTRACT Some individuals with normal hearing thresholds (NHTs) demonstrate considerable challenges perceiving speech in the presence of background noise. Evidence from recent studies suggests that this impairment may be the result of cochlear synaptopathy (CS), degeneration of the synapses between cochlear hair cells and the auditory nerve, observed in animal models following exposure to high-intensity noise that does not permanently alter hearing thresholds. Still, it is not known exactly how noise-induced CS would contribute to impairments in speech-in-noise perception in humans with NHTs. CS engenders auditory nerve fiber degeneration and weakens auditory nerve phase-locking to the precise timing information in auditory signals; therefore, the goal of this research is to determine whether temporal processing impairments from noise- induced CS are consistent with speech-in-noise perceptual deficits in listeners with NHTs. This investigation will contrast listeners with high- and low-likelihood of noise-induced CS, as assessed by a measure of summed auditory nerve fiber responses, on two mechanisms for segregating speech streams that depend on accurate coding of precise timing information. Aim #1 of this investigation will examine use of interaural timing difference cues for spatial attention to speech streams and the degree to which attention to a target stream modulates cortical responses. Aim #2 will utilize a novel task to assess participants’ ability to use pitch cues that can only be coded by auditory nerve phase-locking to perceptually separate speech streams. Cortical entrainment to the temporal envelope of speech, which has been shown to increase perceptual representation of individual streams, will also be examined during this paradigm. Compared to participants with a low likelihood of CS, it is expected that those with a high likelihood of having CS will perform more poorly on tasks that require use of precise timing cues to segregate speech sounds from competing streams. These listeners should also demonstrate lower cortical modulation and neural synchrony to speech streams, demonstrating that bottom-up deficits in temporal encoding alter neural representations of speech in the presence of competing sounds. These findings will provide support for a link between noise-induced CS and impaired speech understanding in noise in listeners with NHTs and will provide valuable knowledge of the contributors to this communication impairment. This research will take place in an exceptional training environment and the PI will be mentored by two knowledgeable, accomplished scientists. These experiments will provide the PI with training in psychophysical task construction, brain activity recording, and signal processing methods and will prepare her well for a career as an independent scientist.

项目概要/摘要 一些听力阈值 (NHT) 正常的人表现出相当大的挑战 在背景噪音存在的情况下感知语音。最近研究的证据表明 这种损伤可能是耳蜗突触病（CS）、耳蜗退化的结果 在动物模型中观察到耳蜗毛细胞和听觉神经之间的突触 暴露于不会永久改变听力阈值的高强度噪音。尽管如此，它仍然不是 确切地知道噪声引起的 CS 将如何导致噪声中语音损伤 患有 NHT 的人的感知。 CS导致听觉神经纤维变性并减弱 听觉神经锁相到听觉信号中的精确定时信息；因此， 这项研究的目标是确定时间处理是否因噪声而受损 诱发的 CS 与 NHT 听众的噪声中语音感知缺陷一致。这 调查将根据评估结果将听众与噪声诱发 CS 的可能性高低进行对比 通过测量听觉神经纤维反应的总和，了解两种分离机制 依赖于精确定时信息的精确编码的语音流。目标#1 调查将检查如何使用耳间时间差异线索来提高言语的空间注意力 流以及对目标流的注意力调节皮质反应的程度。目的 #2 将利用一项新颖的任务来评估参与者使用只能编码的音调线索的能力 通过听觉神经锁相来感知分离语音流。皮质夹带 语音的时间包络，已被证明可以增加感知表征 各个流的数据，也将在此范式中进行检查。与参加者相比 患有 CS 的可能性较低，预计患有 CS 的可能性较高的人将执行 在需要使用精确的时间线索来区分语音和语音的任务上表现更差 竞争流。这些听众还应该表现出较低的皮质调节和神经 与语音流的同步，证明时间编码中自下而上的缺陷会改变 存在竞争声音时语音的神经表征。这些发现将 为噪声引起的 CS 与噪声中语音理解受损之间的联系提供支持 在 NHT 的听众中，并将提供贡献者的宝贵知识 沟通障碍。这项研究将在特殊的培训环境中进行 PI 将由两位知识渊博、成就斐然的科学家指导。这些实验 将为 PI 提供心理物理任务构建、大脑活动记录和 信号处理方法，将为她作为一名独立科学家的职业生涯做好准备。