Sun Kan, Kardous Chucri A, Shaw Peter B, Kim Brian, Mechling Jessie, Azman Amanda S
Pittsburgh Mining Research Division, NIOSH, Pittsburgh.
Division of Applied Research and Technology, NIOSH, Cincinnati, OH, USA.
Noise Control Eng J. 2019 Jan 1;67(1):23-30. doi: 10.3397/1/37673.
Many mobile sound measurement applications (apps) have been developed to take advantage of the built-in or fit-in sensors of the smartphone. One of the concerns is the accuracy of these apps when compared to professional sound measurement instruments. Previously, a research team from the National Institute for Occupational Safety and Health (NIOSH) developed the NIOSH Sound Level Meter (SLM) app for iOS smart devices. The team found the average accuracy of this app to be within ±1 dBA when using calibrated external microphones with a type 1 reference device and measuring pink noise at levels from 65 to 95 dBA in 5-dBA increments. The studies were conducted in a reverberant noise chamber at the NIOSH Acoustics Laboratory in Cincinnati. However, it is still unknown how this app performs in measuring industrial/mining sound levels outside of a controlled laboratory environment. The current NIOSH study evaluates the NIOSH SLM app to measure sound levels from a jumbo drill (a large mining machine). The study was conducted in a hemi-anechoic chamber at the NIOSH Pittsburgh Mining Research Division and followed by a field evaluation in an underground metal mine. Six different iOS smart devices were used with two types of external microphones chosen from previous studies to measure sound levels during jumbo drill operations, and the results were compared with a reference device. Results show that the average sound levels measured by the NIOSH SLM app are within ±1 dBA of the reference device both in the laboratory and field. However, the type of operation being performed, the selection and use of external microphones, distance from a noise source, and environmental factors (e.g., air movement) may all influence the accuracy of the app's performance. Although additional validation is still needed, the results from this study suggest a potential for using the NIOSH SLM app, with calibrated external microphones, to measure sound levels in mining operations.
许多移动声音测量应用程序（应用）已被开发出来，以利用智能手机的内置或适配传感器。其中一个担忧是，与专业声音测量仪器相比，这些应用的准确性如何。此前，美国国家职业安全与健康研究所（NIOSH）的一个研究团队为iOS智能设备开发了NIOSH声级计（SLM）应用。该团队发现，当使用经过校准的外部麦克风和1型参考设备，并在65至95 dBA的范围内以5 dBA的增量测量粉红噪声时，该应用的平均准确度在±1 dBA以内。这些研究是在辛辛那提的NIOSH声学实验室的混响噪声室中进行的。然而，该应用在受控实验室环境之外测量工业/采矿声级时的表现仍不清楚。当前的NIOSH研究评估了NIOSH SLM应用在测量大型钻机（一种大型采矿机器）声级方面的性能。该研究在NIOSH匹兹堡采矿研究部的半消声室中进行，随后在一个地下金属矿中进行了现场评估。使用了六种不同的iOS智能设备，搭配从之前研究中挑选出的两种外部麦克风，在大型钻机作业期间测量声级，并将结果与参考设备进行比较。结果表明，无论是在实验室还是现场，NIOSH SLM应用测量的平均声级都在参考设备的±1 dBA以内。然而，正在执行的操作类型、外部麦克风的选择和使用、与噪声源的距离以及环境因素（如空气流动）都可能影响该应用性能的准确性。尽管仍需要进一步验证，但这项研究的结果表明，使用配备经过校准的外部麦克风的NIOSH SLM应用来测量采矿作业中的声级具有潜力。
