Role of Efferent System in Occupational Hearing Loss

描述(申请人提供)：计划在城市进行的实验 消防员对一系列研究中的发现进行了跟进 在过去的一年里在实验动物对象上进行了实验。使用以下措施 2f1-f2的失真产物耳声发射(DPOAE)，这些之前 调查的目的是检验这样一个假设，即 耳蜗神经传出系统与耳蜗肌功能减退呈负相关。 通过暴露在标准八度频段的噪声中产生的发射活动 (OBN)。也就是说，对豚鼠和兔来说，低剂量的传出系统 活动，通过称为传出的定制双耳DPOAE测试进行索引 总和，随后与更大数量的噪声诱导有关 排放水平的降低。相反，较高的ES分数与 接触OBN后DPOAE减少较少。加在一起，这些 研究结果表明，ES测试是一种很好的有害预测指标 由于暴露在过度的声音中而产生的后遗症。该计划的主要目标是 拟议的实验是为了测试ES测试预测减排的有效性。 在DPOAE中，因此在耳蜗功能中，在一群消防员中作为 接触工作噪声的时间长短的函数。虽然这项工作 将通过在1-2年内监控DPOAE和ES测试来专注于新员工 期间，受雇未满5年的其他工人 消防员也将使用相同的程序进行监控。本研究 将在性别和种族多元化的人口中提供一组独特的数据 承诺确定噪音导致听力损失的风险的工作人员。 因此，拟议的按顺序进行的调查有可能导致 一种高级测试的发展，这将对听力保护有帮助 作为职业相关听力的早期检测程序 损失。

DESCRIPTION (provided by applicant): The planned experiment in urban firefighters follows up on the findings obtained in a series of studies performed this past year on laboratory animal subjects. Using measures of distortion-product otoacoustic emissions (DPOAEs) at 2f1 -f2, these prior investigations were designed to test the hypothesis that the robustness of the cochlear efferent system was inversely related to the amount of reduction in emitted activity produced by exposure to a standardized octave band of noise (OBN). That is, for both guinea pigs and rabbits, low amounts of efferent-system activity, as indexed with a customized binaural DPOAE test called the efferent sum (ES), were subsequently associated with greater amounts of noise-induced decrements in emission levels. In contrast, high ES scores were related to lesser reductions in DPOAEs following exposure to the OBN. Together, these findings suggest that the ES test is a good predictor of the harmful aftereffects produced by exposure to excessive sounds. The primary aim of the proposed experiment is to test the efficacy of the ES test to predict reductions in DPOAEs, and, thus, in cochlear function, in a group of firefighters as a function of the length of exposure to job-related noises. Although the work will focus on new recruits by monitoring DPOAEs and the ES test over a 1-2 year period, other workers, who have been employed for less than 5 years as firefighters will also be monitored using the identical procedures. This study will provide a unique set of data in a gender and ethnically diverse population of workers that promises to determine the risk of noise-induced hearing loss. Thus, the proposed serially-based investigation has the potential of leading to the development of a superior test that would make a useful addition to hearing-conservation programs as an early detector of occupationally related hearing loss.