Peripheral Auditory System Function in Humans: Continuum of Maturation and Aging

人类外周听觉系统功能：成熟和衰老的连续过程

• 批准号: 7850255
• 负责人: Carolina Abdala
• 金额: $ 22.64万
• 依托单位: HOUSE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-17 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7850255
• 关键词: 2 year old; Accounting; Address; Adolescent; Adult; Age; Aging; Aging-Related Process; Amplifiers; Arts; Auditory; Auditory Perception; Auditory Physiology; Auditory system; Basilar Membrane; Biological; Biological Assay; Birth; Characteristics; Child; Childhood; Clinical; Cochlea; Communication; Contralateral; Diagnosis; Ear; Elderly; Evaluation; External auditory canal; Frequencies; Generations; Goals; Health; Hearing; Hearing Tests; Human; Individual; Infant; Intervention; Knowledge; Laboratories; Lead; Life; Longevity; Measurement; Measures; Medial; Methodology; Metric; Newborn Infant; Noise; Outer Hair Cells; Pattern; Perception; Performance; Peripheral; Phase; Physiology; Play; Population; Premature Infant; Prevalence; Principal Investigator; Process; Publishing; Reflex action; Relative (related person); Role; Signal Transduction; Source; Specific qualifier value; Speech; Speech Perception; Stimulus; Structure; System; Techniques; Testing; Time; TimeLine; Work; age group; age related; base; clinical practice; indexing; middle age; neonate; novel strategies; otoacoustic emission; postnatal; premature; research study; response; tool; young adult

DESCRIPTION (provided by applicant): The long-term goals of this project are to investigate changes in peripheral auditory function during maturation and aging and to investigate the relationship between these changes and concomitant changes in auditory perception. Specifically, we will: (1) define the time course for maturation and aging of distortion product otoacoustic emission (DPOAE) fine structure and the individual components comprising the distortion product, (2) define the time course for maturation and aging of the medial olivocochlear (MOC) reflex and (3) relate the observed changes in peripheral auditory physiology to changes in speech perception throughout the human lifespan. Past work has established that peripheral immaturities in the auditory system exist postnatally but the time course for maturation has not been defined, nor have the sources of this immaturity been fully specified. Experiments in this project will allow us to complete the maturational time line, examine the sources of immaturity by studying auditory function at multiple levels of the system, and consider how these changes in peripheral function impact communicative ability. The objectives will be achieved by implementing a novel approach that considers change in peripheral auditory function throughout the human lifespan as a continuum, including both maturational and aging processes. The first aim will be addressed by measuring DPOAE fine structure to parse out the relative contribution from two basilar membrane sources: the DPOAE generator region and the DP characteristic frequency (CF) region. State-of-the-art swept-tone methodology will be used in eight age groups ranging from premature infants to elderly adults. There are currently no published studies of DPOAE fine structure in infants although this issue may be highly relevant to questions of cochlear maturation. The second aim will be accomplished by implementing a DPOAE contralateral noise technique to measure MOC reflexes in the same eight age groups at three frequencies. This paradigm will take into account each subject's individual DPOAE fine structure pattern and record the MOC reflex at response peaks (maxima) only, to control for the relationship between DPOAE components during maturation and aging. The third aim will be accomplished by measuring speech perception in noise along with the two previously described metrics of peripheral auditory function, in adolescent through elderly subjects. This experiment will examine the relationship between changes in the periphery and communicative ability and define the extent to which changes in auditory peripheral physiology throughout life can account for changes in perception. This work is relevant to hearing health and clinical practice because it will provide a normative framework for changes in auditory peripheral function from birth through old age. Furthermore, defining DPOAE fine structure in the pediatric population will help specify which cochlear regions are evaluated during routine DPOAE hearing tests and, thus, have the potential to increase accuracy of hearing diagnoses in children. Finally, this project will lead to a clearer understanding of how natural changes in auditory peripheral function contribute to diminishing speech perception in latter years and will help parse out peripheral versus central contributions to this decline. This work will provide a normative framework for natural changes in auditory peripheral function during maturation and aging and will help specify which cochlear regions (and frequencies) are actually assessed during a routine pediatric hearing evaluation using otoacoustic emissions. This information has the potential to increase the sophistication and accuracy of hearing evaluations and thus, of subsequent intervention. This work will also lead to an understanding of how natural, lifetime changes in auditory peripheral function contribute to diminishing speech perception during the latter decades of life and help parse out peripheral versus central contributions to this decline.

描述（由申请人提供）：该项目的长期目标是研究成熟和衰老过程中外周听觉功能的变化，并研究这些变化与随之而来的听觉感知变化之间的关系。具体来说，我们将：（1）定义畸变产物耳声发射（DPOAE）精细结构和构成畸变产物的各个成分的成熟和老化的时间过程，（2）定义内侧橄榄耳蜗的成熟和老化的时间过程（MOC）反射和（3）将观察到的周围听觉生理学变化与整个人类一生中言语感知的变化联系起来。过去的研究已经证实，听觉系统的外围不成熟在出生后就存在，但尚未确定成熟的时间过程，也没有完全明确这种不成熟的根源。该项目中的实验将使我们能够完成成熟时间线，通过研究系统多个层面的听觉功能来检查不成熟的根源，并考虑外围功能的这些变化如何影响沟通能力。这些目标将通过实施一种新颖的方法来实现，该方法将整个人类生命周期中外周听觉功能的变化视​​为一个连续体，包括成熟和衰老过程。第一个目标将通过测量 DPOAE 精细结构来解析两个基底膜源的相对贡献：DPOAE 发生器区域和 DP 特征频率 (CF) 区域。最先进的扫频方法将用于从早产儿到老年人的八个年龄组。目前尚未发表有关婴儿 DPOAE 精细结构的研究，尽管这个问题可能与耳蜗成熟问题高度相关。第二个目标将通过实施 DPOAE 对侧噪声技术来测量相同八个年龄组中三个频率的 MOC 反射来实现。该范例将考虑每个受试者的个体 DPOAE 精细结构模式，并仅记录响应峰值（最大值）处的 MOC 反射，以控制成熟和衰老过程中 DPOAE 成分之间的关​​系。第三个目标将通过测量青少年到老年受试者在噪声中的言语感知以及先前描述的外周听觉功能的两个指标来实现。该实验将检查外围变化与交流能力之间的关系，并确定一生中听觉外围生理学的变化在多大程度上可以解释感知的变化。这项工作与听力健康和临床实践相关，因为它将为从出生到老年的听觉周围功能的变化提供规范框架。此外，定义儿科人群的 DPOAE 精细结构将有助于明确在常规 DPOAE 听力测试期间评估哪些耳蜗区域，从而有可能提高儿童听力诊断的准确性。最后，该项目将导致人们更清楚地了解听觉外围功能的自然变化如何导致晚年言语感知的减弱，并将有助于解析外围与中枢对这种下降的贡献。这项工作将为成熟和衰老过程中听觉周围功能的自然变化提供一个规范框架，并将有助于明确在使用耳声发射进行常规儿科听力评估期间实际评估哪些耳蜗区域（和频率）。这些信息有可能提高听力评估的复杂性和准确性，从而提高后续干预的复杂性和准确性。这项工作还将有助于了解听觉外围功能的自然终生变化如何导致生命后几十年言语感知的减弱，并有助于解析外围与中枢对这种下降的贡献。