Neural correlates of auditory function and training in older adults

描述(由申请人提供)：许多老年人在背景噪音中感知语音时遇到了极大的困难。为什么这种情况会发生在一些老年人身上，但不是所有老年人身上，这是一个目前还没有答案的问题。我们的长期目标是了解老年人在噪音中语音感知的生物学基础，并利用这些知识通过训练来提高感知能力。越来越多的证据表明，听觉感觉系统(包括耳蜗力学和脑干)是动态的，可以通过短期(训练)和终身(语言和音乐)经验来塑造。正常的言语交流有赖于神经系统对声音的准确转录，尤其是在嘈杂的背景下。在老龄化人口中，这种转录过程的失败代表着巨大的社会和经济成本，相当大的资源被投入到可能不起作用的治疗上。在诊断和治疗方案的评估方面缺乏客观评估。此外，有新的证据表明，听觉外周是由高级中枢通过传出系统调节的，以帮助在背景噪音中倾听。这一贡献仍有待于对人类物种的任何细节进行表征和/或量化。因此，我们的目标是确定老年人在噪音中语音的脑干转录，这种转录如何与耳蜗力学的测量有关，以及转录与训练的可塑性。我们的中心假设是转录准确性和耳蜗力学的干扰是噪声中听损伤的因素，并且干扰可以通过干预来补救。这项拟议工作的结果将揭示老年人在噪音中与言语感知有关的感觉机制，并确定短期训练产生的基本感觉回路的可塑性。这一结果将对我们理解和客观评估老年人的感觉功能产生积极的影响。 与公共健康相关：正常的语言交流依赖于神经系统对声音的准确转录，特别是在嘈杂的背景下。许多老年人在背景噪音中经历了理解语音的过度困难，因为在某种程度上，转录过程已经崩溃。我们的第一个目标是调查转录的最早水平--耳蜗力学和脑干编码--并确定它们可能在多大程度上导致问题，从而潜在地导致一个客观的衡量标准。第二个目标是调查基于培训的补救措施对这些早期处理水平的影响程度。这一结果将对我们理解和客观评估老年人的感觉功能产生积极的影响。

DESCRIPTION (provided by applicant): Many older adults experience excessive difficulty perceiving speech in background noise. Why this occurs for some, but not all older individuals is a question that currently has no answer. Our long-term goal is to understand the biological bases of speech-in-noise perception in older adults and to use that knowledge to improve perception through training. Converging evidence indicates that the auditory sensory system (including cochlear mechanics and brainstem) is dynamic and can be shaped by short-term (training) and lifelong (language and music) experience. Normal verbal communication depends on the accurate transcription of sound by the nervous system, especially in noisy backgrounds. Failure of this transcription process in the aging population represents a huge social and financial cost, and considerable resources are invested in treatments that may not work. Little objective assessment exists in diagnosis and evaluation of treatment options. Further, there is emerging evidence that the auditory periphery is modulated by higher centers via the efferent system to aid listening in background noise. This contribution remains to be characterized and/or quantified in any detail in the human species. Accordingly, our objectives are to determine brainstem transcription of speech sounds in noise in older adults, how this transcription relates to measures of cochlear mechanics, and the plasticity of transcription with training. Our central hypothesis is that disruption of transcription accuracy and cochlear mechanics are factors in listening-in-noise impairments, and that disruption can be remedied by intervention. The outcome of the proposed work will reveal sensory mechanisms linked to speech perception in noise in older adults and determine plasticity of basic sensory circuitry arising from short-term training. This outcome will have a positive impact on our understanding and objective assessment of sensory function in aging adults. PUBLIC HEALTH RELEVANCE: Normal verbal communication depends on the accurate transcription of sound by the nervous system, especially in noisy backgrounds. Many older adults experience excessive difficulty understanding speech in background noise because, at some level, the transcription process has broken down. Our first objective is to investigate the earliest levels of transcription-cochlear mechanics and brainstem encoding - and determine the extent to which they may contribute to the problem, thereby potentially leading to an objective metric. The second objective is to investigate the extent to which a training-based remedy affects these early processing levels. This outcome will have a positive impact on our understanding and objective assessment of sensory function in aging adults.