Objective: To get insight into the current practice of noise reduction effect of workers as they wore hearing protectors in different domestic enterprises and the possible affected factors. Methods: From October 2020 to April 2021, using a random sampling method, 1197 workers exposed to noise in petrochemical factories, textile factories, and parts manufacturing factories were selected as the study subjects. The noise reduction effect of hearing protectors worn by workers in daily use was tested using a hearing protector suitability testing system. The personal sound attenuation level (PAR) was compared among workers in three enterprises, Targeted intervention and repetitive testing were conducted for workers who did not meet the noise reduction effect required by the enterprise, and the changes in PAR of workers before and after the intervention were compared. The comparison of baseline PARs between two or more groups was performed using the Mann Whitney test, the comparison of baseline PARs with post intervention PARs was performed using the Wilcoxon signed rank sum test, and the comparison of qualitative data between two or more groups was performed using the Chi square test. Results: The median baseline PAR for all workers was 15 dB. Men, age<30 years old, education level at or above college level, working experience of 5 to 15 years, and those who used hearing protectors for 5 to 15 years had higher PARs, with statistically significant differences (P<0.05). The median difference in baseline PAR among workers from three enterprises was statistically significant (H=175.06, P<0.01). The median PAR of subjects who did not pass the baseline increased from 3 dB to 21 dB after intervention (Z=-27.92, P<0.01) . Conclusion: Some workers wearing hearing protectors do not meet the required PAR, and low PARs may be related to incorrect wearing methods and incorrect selection of hearing protectors. As a tool for testing, training, and assisting in selection, the hearing protector suitability testing system is of great significance for worker hearing protection.
目的： 了解国内不同行业的工人使用护听器的降噪效果现状及其影响因素。 方法： 于2020年10月至2021年4月，采用随机抽样的方法，选取石化厂、纺织厂、零部件制造厂1 197名噪声作业工人为研究对象，利用护听器适合性检验系统测试工人佩戴日常使用的护听器的降噪效果[个人声衰减值水平（PAR）]，比较3家企业工人的PAR，对于未达到企业要求降噪效果的工人进行针对性的干预和重复性测试，比较干预前后工人的PAR的变化情况。两组或多组基线PAR的比较用曼惠特尼检验，基线PAR与干预后PAR的比较用威尔科克森符号秩和检验，两组或多组定性资料的比较用χ(2)检验。 结果： 所有工人的基线PAR的中位数为15 dB，男性、年龄<30岁，文化程度在大专及以上、工龄5~15年，使用护听器5~15年者的PAR值较高，差异均有统计学意义（P<0.05）。三家企业工人的基线PAR中位数差异有统计学意义（H=175.06，P<0.01）。未通过基线受试者的PAR的中位数经干预后从3dB提升至21 dB（Z=-27.92，P<0.01）。 结论： 部分工人佩戴护听器并未达到要求的PAR，低PAR可能与不正确的佩戴方式和不正确护听器选型有关，护听器适合性检验系统作为一项检测、培训和帮助选型的工具对于工人听力保护具有重要意义。.
Keywords: Attenuation; Epidemiologic factors; Hearing protectors; Individual fit testing; Noise.