How does the efferent auditory system function in the neural encoding and perception of speech-in-noise?

传出听觉系统在噪声中语音的神经编码和感知中如何发挥作用？

基本信息

批准号：
9117990
负责人：
Spencer Smith
金额：
$ 3.13万
依托单位：
UNIVERSITY OF ARIZONA
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：
2014-08-20 至 2017-08-19
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9117990
关键词：
Academic achievement Acoustic Nerve Action Potentials Active Listening Address Adult Affect Aging Algorithms Animal Experimentation Animals Auditory Auditory Brainstem Responses Auditory Perception Auditory system Biological Assay Brain Brain Stem Child Cochlea Cochlear Implants Code Cognitive Consensus Contralateral Data Ear Electrophysiology (science)Evaluation External auditory canal Feedback Functional disorder Goals Hearing Hearing Aids Human Impairment Individual Labyrinth Language Lead Learning Disorders Left Masks Measurement Measures Mechanics Medial Modeling Nervous system structure Neurobiology Noise Outcomes Research Output Participant Patients Perception Physiological Process Reading Recruitment Activity Reflex action Research Role Signal Transduction Site Speech Speech Perception Structure of tractus olivocochlearis System Time Withdrawal Work base disability experience improved nerve supply neural circuit neurotransmission noise perception otoacoustic emission public health relevance relating to nervous system research study response social speech processing targeted treatment

项目摘要

DESCRIPTION (provided by applicant): Severe difficulty understanding speech-in-noise causes social withdrawal, inhibits academic achievement, and limits vocational opportunities for those affected. Inexplicably, there are individuals who experience severe difficulty understanding speech-in-noise despite having normal hearing sensitivity, such as normally aging adults and children with reading, language, auditory processing, and learning disorders. The neurobiological basis of speech-in-noise deficits in these individuals is currently unknown, which limits evaluation and targeted treatment of this hearing disability. The efferent auditory system is the division of the auditory nervous system that is believed to fine-tune and filter auditory information as it ascends from the inner ears to the brain. This system has been studied extensively in animals, but far less is known about how it works in humans during speech-in-noise processing. Some evidence suggests that selective dysfunction in the efferent auditory system may cause severe difficulty hearing in noise while leaving hearing sensitivity intact. The proposed research investigates the function of one specific mechanism of the human efferent auditory system, the medial olivocochlear (MOC) bundle, in the neural encoding and perception of speech-in-noise in normal hearing adults and children. The MOC bundle is an efferent neural circuit, which has been shown to filter and suppresses background noise at the level of the inner ear in animals. This filter may allow less noise to be transcribed into neural code, which in turn improves perception of auditory signals in competing background noise. It remains unclear if the human MOC reflex is: a) an important efferent mechanism that reduces the effect of noise on the bottom-up neural encoding of speech, and b) modulated by top-down processes, such as active listening, to enhance hearing in noise. These issues will be addressed in two studies. The first study will involve measurements of speech-evoked neural activity from the auditory nerve and brainstem during MOC reflex activation to determine if this reflex improves the neural encoding of speech-in-noise. It is hypothesized that activation of the MOC reflex will improve the neural encoding of speech-in-noise at the level of the auditory nerve and brainstem. In the second study, participants will actively listen to an Auditory Stroop Task while the MOC reflex is engaged to determine if cognitive demands modulate the MOC reflex. It is hypothesized that more challenging listening conditions of the Auditory Stroop Task will have a greater impact on MOC reflex strength, indicating a modulatory relationship between the brain and inner ears. The outcomes of this research clarify the role of the efferent system in speech-in-noise processing and can be used to create targeted treatments and objective assessments for individuals with severe difficulties understanding speech-in-noise.

描述（由申请人提供）：理解噪声中的语音严重困难会导致社交退缩，抑制学业成就，并限制受影响者的职业机会。令人费解的是，有些人尽管听力敏感度正常，但在理解噪声中的语音时却遇到严重困难，例如患有阅读、语言、听觉处理和学习障碍的正常老年人和儿童。这些人在噪声中言语缺陷的神经生物学基础目前尚不清楚，这限制了对这种听力障碍的评估和有针对性的治疗。传出听觉系统是听觉神经系统的一部分，被认为可以在听觉信息从内耳上升到大脑时对听觉信息进行微调和过滤。该系统已在动物身上进行了广泛的研究，但人们对其在噪声处理中的语音处理过程中如何在人类中发挥作用知之甚少。一些证据表明，传出听觉系统的选择性功能障碍可能会导致在噪音中听力严重困难，同时保持听力敏感性完好。拟议的研究调查了人类传出听觉系统的一种特定机制，即内侧橄榄耳蜗（MOC）束，在正常听力成人和儿童的噪声中语音的神经编码和感知中的功能。 MOC 束是一种传出神经回路，已被证明可以过滤和抑制动物内耳水平的背景噪音。该滤波器可以允许更少的噪声被转录成神经代码，从而改善竞争背景噪声中听觉信号的感知。目前尚不清楚人类 MOC 反射是否是：a）一种重要的传出机制，可减少噪声对自下而上的语音神经编码的影响；b）通过自上而下的过程（例如主动聆听）进行调节，以增强听力在噪音中。这些问题将在两项研究中得到解决。第一项研究将测量 MOC 反射激活过程中听觉神经和脑干的言语诱发神经活动，以确定这种反射是否改善噪声中言语的神经编码。据推测，MOC 反射的激活将改善听觉神经和脑干水平的噪声中语音的神经编码。在第二项研究中，参与者将积极聆听听觉斯特鲁普任务，同时参与 MOC 反射，以确定认知需求是否调节 MOC 反射。据推测，听觉斯特鲁普任务中更具挑战性的听力条件将对 MOC 反射强度产生更大的影响，表明大脑和内耳之间的调节关系。这项研究的结果阐明了传出系统在噪声中语音处理中的作用，可用于为理解噪声中语音有严重困难的个体创建有针对性的治疗和客观评估。