Aliabadi Mohsen, Biabani Azam, Golmohammadi Rostam, Farhadian Maryam
Center of Excellence for Occupational Health, Occupational Health and Safety Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
Center of Excellence for Occupational Health, Research Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran.
Work. 2018;60(2):271-279. doi: 10.3233/WOR-182726.
Actual noise reduction of the earmuffs is considered as one of the main challenges for the evaluation of the effectiveness of a hearing conservation program.
The current study aimed to determine the real world noise attenuation of current hearing protection devices in typical workplaces using a field microphone in real ear (FMIRE) method.
In this cross-sectional study, five common earmuffs were investigated among 50 workers in two industrial factories with different noise characteristics. Noise reduction data was measured with the use of earmuffs based on the ISO 11904 standard, field microphone in real ear method, using noise dosimeter (SVANTEK, model SV 102) equipped with a microphone SV 25 model.
The actual insertion losses (IL) of the tested earmuffs in octave band were lower than the labeled insertion loss data (p < 0.05). The frequency nature of noise to which workers are exposed has noticeable effects on the actual noise reduction of earmuffs (p < 0.05). The results suggest that the proportion of time using earmuffs has a considerable impact on the effective noise reduction during the workday.
Data about the ambient noise characteristics is a key criterion when evaluating the acoustic performance of hearing protectors in any workplaces. Comfort aspects should be considered as one of the most important criteria for long-term use and effective wearing of hearing protection devices. FMIRE could facilitate rapid and simple measurement of the actual performance of the current earmuffs employed by workers during different work activities.
耳罩的实际降噪效果被视为听力保护计划有效性评估的主要挑战之一。
本研究旨在使用真耳现场麦克风（FMIRE）方法确定当前听力保护设备在典型工作场所的实际降噪效果。
在这项横断面研究中，对两家具有不同噪声特征的工业工厂的50名工人所使用的五种常见耳罩进行了调查。根据ISO 11904标准，采用配备SV 25型号麦克风的噪声剂量计（SVANTEK，型号SV 102），通过真耳现场麦克风方法测量使用耳罩时的降噪数据。
测试耳罩在倍频程频段的实际插入损失（IL）低于标签标注的插入损失数据（p<0.05）。工人接触的噪声频率特性对耳罩的实际降噪效果有显著影响（p<0.05）。结果表明，使用耳罩的时间比例对工作日期间的有效降噪有相当大的影响。
在评估任何工作场所听力保护器的声学性能时，环境噪声特征数据是一个关键标准。舒适度应被视为听力保护设备长期使用和有效佩戴的最重要标准之一。FMIRE可以方便快捷地测量工人在不同工作活动中使用的当前耳罩的实际性能。
