噪声作业工人不同频率听力改变特征分析

Changes of hearing ability at different frequency in noise exposure workers

目的分析噪声接触对作业工人不同频率听力的影响。方法采用判断抽样方法,以广州市某机械制造厂2 411名噪声作业工人为研究对象,对其进行纯音听阈测试,分析不同频率听阈损失情况及其与噪声作业工龄的关系。结果 2 411名噪声作业工人中,883人有不同程度的听阈下降,检出率为36.6%;其中,仅单耳听力损失检出率为19.6%(472/2 411),双耳听力损失检出率为17.0%(411/2 411)。研究对象左耳听力损失检出率高于右耳(P<0.05),且左耳0.5、3.0和6.0 kHz频率听阈下降的检出率均高于右耳相同频率(P<0.05);左耳和右耳听阈下降的检出率均随频率的升高而增加(P<0.01),均以6.0 kHz频率听阈下降的检出率最高。左耳0.5、1.0、2.0、3.0和6.0 kHz频率的听阈均高于右耳相同频率(P<0.05)。研究对象听力损失检出率随噪声作业工龄的增加而增加(P<0.01);除0.5 kHz频率外,1.0~6.0 kHz频率听阈下降的检出率均随噪声作业工龄的增加而增加(P<0.05)。结论噪声作业工人听阈下降以6.0 kHz频率较为显著;左耳听力较右耳易受损;噪声接触时间与各频率的听力损失存在剂量-效应关系。

Objective To analyze the effect of noise exposure on the hearing ability at different frequency in workers.Methods A total of 2 411 workers in a mechanical plant in Guangzhou were chosen as the study subjects by using judgment sampling method. The pure tone audiometry threshold test was carried out to analyze the status of hearing loss at different frequencies and its relationship with the length of service of workers. Results Among the 2 411 workers,883 workers had different degrees of decreased hearing thresholds,the detection rate was 36. 6%. Among them,the single unilateral hearing loss accounted for 19. 6%（ 472/2 411）,and the binaural hearing loss was 17. 0%（ 411/2 411）. The hearing loss detection rate of left ear was higher than that of the right ear（ P〈0. 05）. The decreased threshold of left ear at 0. 5,3. 0 and 6. 0 kHz was higher than that of the right ear at the same frequencies（ P〈0. 05）. The decreased threshold in both the left and the right ear increased with the increase of the frequency（ P〈0. 01）. The decreased hearing threshold was the highest at the frequency of 6. 0 kHz. The auditory threshold of left ear in 0. 5,1. 0,2. 0,3. 0 and 6. 0 kHz were higher than that of right ear at the same frequencies（ P〈0. 05）. The detection rate of hearing loss increased with the increase of service length（ P〈0. 01）. The decreased threshold of 1. 0-6. 0 kHz increased with the increased length of service except for the frequency of 0. 5 kHz（ P〈0. 05）. Conclusion There is a significant decreased threshold in workers exposed to noise frequency of 6. 0 kHz. The hearing ability of left ear is more easily impaired than the right ear.There is a dose-response relationship for the length of noise exposure and hearing loss.