EFFECTS OF MICROPHONE PLACEMENT ON DOSIMETRY MONITORING OF INDUSTRIAL NOISE

该协议正在测试麦克风位置影响的假设 由剂量计计算的噪声剂量，也称为积分 声级计。一个辅助目标是检查个体差异。 在受试者耳道中测量的投射剂量。三 使用了每个20分钟的测量条件。他们是作为 已知的是：在耳道内放置一个探针管麦克风 距鼓膜的距离；将麦克风放在右侧 肩部；以及将麦克风放在左乳房口袋上。这个 受试者被指示恢复他/她的正常工作程序 噪声剂量正在监测中。此外，一种固定的测量是 用安装在三脚架上的麦克风拍摄的。然后下载数据 发送到PC，并分析不同 测量。 这项研究正在与#司合作进行。 使用NIH员工的NIH空调冷水机组工厂的安全。一个 共有10名成人受试者将被使用。到目前为止，已经收集了数据 关于两个主题。主要差异表现在较高的投射剂量上 在鼓膜处测量与躯干的其他位置和 静态测量。虽然并不令人惊讶，但这些数据表明 考虑整个声道的声学的重要性 在评估听力损失的风险时。这些数据挑战了 通过使用以下工具维护度量的同质性的传统智慧 只有一个麦克风站点。

This protocol is testing the hypothesis that microphone site influences the noise dose computed by a dosimeter, otherwise known as an integrating sound level meter. An ancillary goal is to examine individual differences in projected dose measured in the ear canals of the subjects. Three measurement conditions of 20 minutes each are being used. They are as follows: placement of a probe tube microphone into the ear canal a known distance from the eardrum; placement of the microphone on the right shoulder; and placement of the microphone on the left breast pocket. The subject is instructed to resume his/her normal work routine while the noise dose is being monitored. In addition, one stationary measurement is taken with the microphone mounted on a tripod. Data are then downloaded to a PC and analyzed for differences in variance for the different measurements. The study is being conducted with the cooperation of the Division of Safety at the NIH air conditioning chiller plant using NIH employees. A total of 10 adult subjects will be used. To date data have been collected on two subjects. Major differences are shown with higher projected dose being measured at the eardrum vs the other torso positions and the stationary measurement. While not surprising, these data demonstrate the importance of taking into account the acoustics of the entire sound path when assessing risk of hearing loss. These data challenge the conventional wisdom of maintaining homogeneity of measurements by using one microphone site only.