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: 9909656
• 负责人: Mishaela T DiNino
• 金额: $ 6.12万
• 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 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9909656
• 关键词: Acoustic Nerve; Acoustics; Adult; Affect; Animal Experimentation; Animal Model; Area; Attention; Attenuated; Auditory; Auditory Perception; 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; hearing threshold; 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.

项目摘要/摘要 一些听力阈值(NHTS)正常的个体表现出相当大的挑战 在存在背景噪音的情况下感知语音。最近研究的证据表明 这种损害可能是耳蜗性突触病变(CS)的结果， 耳蜗毛细胞与听神经之间突触的动物模型观察 暴露在不会永久改变听力阈值的高强度噪音中。尽管如此，它并不是 确切地知道噪声诱导的CS如何导致噪声中的语音损伤 患有NHTS的人的感知。CS引起听神经纤维变性和弱化 听神经对听觉信号中的精确定时信息进行相位锁定；因此， 这项研究的目标是确定噪声对时间加工的损害 NHTS患者诱发的CS与噪声中言语知觉缺陷是一致的。这 调查将根据评估，将听者与噪音诱发CS的高可能性和低可能性进行对比 通过总和听神经纤维反应的测量，关于分离的两种机制 依赖于精确定时信息的准确编码的语音流。目标1 研究将考察对语音空间注意的耳间时差线索的使用 流，以及对目标流的关注程度对皮质反应的调制。目标 #2将利用一项新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 到语音的时间包络，这已经被证明增加了知觉表征 在这一范例中，也将对个别溪流的情况进行研究。与以下参与者相比 CS的可能性很低，预计那些CS可能性很高的人会表现出 在需要使用精确计时提示将语音声音与 相互竞争的溪流。这些听众还应该表现出较低的皮质调制和神经功能 与语音流同步，表明时间编码中自下而上的缺陷发生了变化 在存在竞争声音的情况下语音的神经表示。这些发现将 支持噪声引起的CS和噪声中的语音理解障碍之间的联系 在NHTS的监听者中，并将提供对此贡献者的宝贵知识 沟通障碍。这项研究将在特殊的培训环境中进行 而PI将由两名知识渊博、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、脑活动记录和 信号处理方法，并将为她作为一名独立科学家的职业生涯做好准备。