Research progress on verification methods on measuring noise attenuation value of hearing protective devices

Abstract

At present, the methods for verifying the attenuation of hearing protective devices (HPDs) mainly include real-ear attenuation at threshold (REAT), microphone in real ear (MIRE), and acoustical test fixture (ATF). Among them, the REAT is the gold standard, but its testing requirements are strict and there is a physiological noise masking effect. The test results of MIRE need to be modified by transfer function of the open ear, which has the advantage of convenient operation without being afected by subjective feelings. The ATF method is mainly used to verify the shape and quality of customized HPDs since its artificial ear design cannot truly refect the real-ear test situation. The HPD fit testing has been well developed and widely applied abroad, which has been proved to be able to accurately verify and effectively improve the attenuation of workers wearing HPDs. However, relevant research and applications have only been carried out in China in recent years. At present, the main problems in the verification of the protective effect of HPDs in China are as follows: firstly, the measurement is only limited in attenuation and fail to comprehensively consider the applicability and comfort of the HPDs; secondly, a-weighted sound pressure level is mostly used in noise monitoring in China, while the choice of HPDs is based on C-weighted-sound pressure level. The transition between these two has not been established. Future research should be devoted to solve the above problems and help the use of HPDs in preventing the hearing loss of noise-exposed workers.

Abstract

摘要： 目前护听器声衰减值的验证方法主要包括真耳听阈衰减法 (REAT)、真耳内置麦克风法 (MIRE) 和声学仿真测量装 置 (ATF)。其中, REAT 法是黄金方法, 但其测试要求严格, 存在生理噪声掩蔽效应; MIRE 法的测试结果则需要进行人耳 传递函数修正, 其优点是操作便捷、不受主观感受影响; ATF 法由于其仿真耳的设计不能真实反映真耳的测试情况, 因此 主要应用于验证定制护听器的形状和质量合格情况。护听器适合性检验在国外已有较成熟的发展应用, 且已被证实能够 准确验证和有效提高工人佩戴护听器的声衰减值, 而国内近年来才开展相关的研究应用。目前国内护听器防护效果验证 的主要问题有:一是仅局限于声衰减值的测定, 未能综合考虑护听器的适用性和舒适性;二是我国噪声监测多采用 A 计权 声压级, 护听器的选择是基于 C 计权声压级, 两者间的过渡未能建立, 未来研究亟需致力于解决以上问题, 帮助发挥护听 器预防噪声作业工人听力损失的作用。