Can noise-induced TTS cause persistent impairment of speech understanding?

描述（由申请人提供）：最近的一项动物实验发现，即使小鼠的长期听力阈值保持正常，暴露于足够的噪音以产生暂时阈值移位（TTS），其听觉功能也会出现意想不到的、持续的阈值以上变化。这些结果与职业噪声暴露指南和法规相冲突，这些指南和法规假设可逆阈值位移（即TTS）与良性暴露水平相关。本研究的目的是确定动物实验的结论是否适用于人类，并如预测的那样，导致对噪音的言语理解受损和/或对响度增长（LG）的感知受到干扰。我们建议研究听力阈值（HLs）正常的成年男性或女性（21 - 50岁），他们要么经常暴露于噪音和/或大声音乐，并有提示噪声诱发的TTS和/或耳鸣的症状（“暴露”组），要么很少或没有暴露于噪音或提示噪声诱发的TTS或耳鸣的症状（“未暴露”组）。志愿者将完成一份问卷，以确定他们的HLs确诊后的症状和暴露情况。多达90名志愿者将参与以下行为测试：1)纯色HLs；(2)使用修饰韵测试在噪声中的单词得分；3)检测纯音正弦调幅的阈值。将对25名“暴露者”和25名“未暴露者”进行数据分析，选择最符合组平均听力阈值的人。该提案涉及听力损失预防跨部门项目和所有可能发生听力损失的NORA部门项目（农业、林业、建筑业、制造业、采矿业和运输业）。确认减少或消除可逆性阈值转移的需要需要中间结果，例如有关职业噪声暴露和听力保护计划的公共政策变化。还需要重新设计听力保护器和改进通信设备，以符合减少危险接触所需的更严格的噪音暴露准则。确定对此类设备的需求将有助于NIOSH的r2P倡议。如果效果被证明只有少数人经历，可能更适合开发旨在弥补LG功能缺陷的设备（见Brammer和Bernstein， 2012）。因此，提供一种快速建立LG功能的方法，如本文所建议的，将有助于NIOSH的r2P倡议，使此类设备的开发成为可能。拟议的研究成果将在会议上提出，并在科学期刊上发表。

DESCRIPTION (provided by applicant): A recent animal experiment found that mice exposed to sufficient noise to produce temporary threshold shift (TTS) experienced unexpected, persistent suprathreshold changes in auditory function even though their long-term hearing thresholds remained normal. The results conflict with occupational noise exposure guidelines and regulations, which assume reversible threshold shifts (i.e., TTS) are associated with benign levels of exposure. The purpose of the proposed study is to establish whether the conclusion of the animal experiment is applicable to man and, as predicted, causes impaired speech understanding in noise and/or perturbed perception of loudness growth (LG). We propose to study adult males or females (aged 21 - 50 years) with normal audiometric hearing thresholds (HLs) who either report frequent exposure to noise and/or loud music and symptoms suggestive of noise-induced TTS and/or tinnitus ("exposed" group), or little or no exposure to noise or symptoms suggestive of noise-induced TTS or tinnitus ("unexposed" group). Volunteers will complete a questionnaire to establish symptoms and exposures after confirmation of their HLs. Up to 90 volunteers will participate in behavioral tests of: 1) pure-tone HLs; 2) word scores in noise using the Modified Rhyme Test, and; 3) thresholds for detecting sinusoidal amplitude modulation of pure tones. The analysis of data will be performed on 25 "exposed" and 25 "unexposed persons selected to best match the group mean audiometric thresholds. The proposal addresses an issue relevant to the Hearing Loss Prevention Cross-Sector Program and all NORA Sector Programs in which hearing loss may occur (Agriculture, Forestry, Construction, Manufacturing, Mining, and Transportation). Confirmation of the need to reduce or eliminate reversible threshold shifts will require intermediate outcomes such as public policy changes concerning occupational noise exposures and hearing conservation programs. There will also be a need for redesigned hearing protectors and improved communication devices to comply with the more restrictive noise exposure guidelines that would be required to reduce hazardous exposures. Identifying the need for such devices would contribute to NIOSH's r2P initiative. Should the effect prove to be experienced by only a few persons, it may be more appropriate to develop devices designed to compensate for a deficiency in the LG function (see Brammer and Bernstein, 2012). Hence, providing a rapid method for establishing the LG function, as proposed here, will contribute to NIOSH's r2P initiative by enabling the development of such devices. The outputs of the proposed research will be presented at conferences and published in scientific journals.