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: 10382033
• 负责人: Mishaela T DiNino
• 金额: $ 1.66万
• 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/10382033
• 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; 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.

项目总结/摘要 一些听力阈值正常的人表现出相当大的挑战 在存在背景噪声的情况下感知语音。最近的研究表明， 这种损害可能是耳蜗突触病（CS）的结果， 耳蜗毛细胞和听神经之间的突触，在动物模型中观察到， 暴露于不会永久改变听力阈值的高强度噪音。然而， 确切地知道噪声诱导的CS如何导致噪声中的语音损伤 NHT患者的感知能力CS引起听神经纤维变性， 听觉神经相位锁定听觉信号中的精确定时信息;因此， 这项研究的目的是确定是否时间处理损伤噪声- 诱发的CS与NHT患者的噪声中语音感知缺陷一致。这 调查将根据评估结果，对具有高和低噪声诱导CS可能性的听众进行对比 通过测量总的听觉神经纤维反应，在两种机制上分离 语音流依赖于精确定时信息的精确编码。目标#1 一项研究将检验两耳间时间差异线索对言语空间注意的作用 流和对目标流的注意调节皮层反应的程度。目的 #2将利用一个新的任务来评估参与者使用只能编码的音高提示的能力 通过听觉神经锁相来感知分离语音流。皮质卷吸 语音的时间包络，这已被证明可以增加感知表示 在此范例中，还将检查单个流。与参与者相比， CS的可能性较低，预计那些具有CS高可能性的人将表现出 更差的任务，需要使用精确的时间线索，以分离语音声音， 竞争的溪流。这些听众还应该表现出较低的皮层调制和神经 同步的语音流，表明自下而上的赤字时间编码改变 在竞争性声音存在的情况下语言的神经表征。这些发现将 为噪声诱导的CS和噪声中言语理解受损之间的联系提供支持 在听众与NHT，并将提供有价值的知识的贡献者， 沟通障碍这项研究将在一个特殊的培训环境中进行 PI将由两位知识渊博的科学家指导。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，并将准备她作为一个独立的科学家的职业生涯。