Kryter K D
San Diego State University, College of Health and Human Services, California 92182.
J Acoust Soc Am. 1991 Dec;90(6):3180-95. doi: 10.1121/1.401427.
Pure-tone hearing thresholds and anamnestic data pertaining to nosocusis and exposure to gun noise were analyzed for 9778 male railroad train-crew workers. A major portion of losses in hearing sensitivity due to railroad noise are obscured in comparisons of hearing levels of trainmen with the hearing levels of the unscreened samples of United States males given in Annex B, ISO 1999 [ISO 1999 (1990), "Acoustics--Determination of occupational noise exposure and estimation of noise-induced hearing impairment" (International Organization for Standardization, Geneva)]. Comparisons of the hearing levels, adjusted for nosocusis, of trainmen who had used no guns, with the hearing levels of otologically and noise screened males (Annex A, ISO 1999) reveal significant losses due to railroad noise. Additional losses were found at high frequencies in trainmen who had used guns. It appears that the effective Leq8h exposure level of trainmen to railroad noise is about 92 dBA, and 87-89 dBA to gun noise. These results are in general agreement with those of study of railway workers by Prosser et al. [Br. J. Audiol. 22, 85-91 (1988)]. Asymmetries in losses between the two ears, effects of ear protection, losses from nosocusis, and losses from sport, as compared to military, gun noise exposures, are examined.
对9778名男性铁路列车乘务员的纯音听力阈值以及与职业性听力损失和枪支噪声暴露相关的既往史数据进行了分析。在将列车员的听力水平与ISO 1999附录B中给出的未筛查的美国男性样本的听力水平进行比较时，铁路噪声导致的听力敏感度损失的很大一部分被掩盖了[ISO 1999 (1990)，《声学——职业噪声暴露的测定和噪声性听力损伤的评估》(国际标准化组织，日内瓦)]。将未使用枪支的列车员经职业性听力损失校正后的听力水平与经过耳科和噪声筛查的男性(ISO 1999附录A)的听力水平进行比较，发现铁路噪声导致了显著的听力损失。在使用过枪支的列车员中，高频段还发现了额外的听力损失。列车员对铁路噪声的有效8小时等效连续A声级暴露水平似乎约为92 dBA，对枪支噪声的暴露水平为87 - 89 dBA。这些结果与Prosser等人对铁路工人的研究结果[《英国听力学杂志》22, 85 - 91 (1988)]基本一致。研究还考察了双耳听力损失的不对称性、耳罩的作用、职业性听力损失、运动导致的听力损失，以及与军事枪支噪声暴露相比的情况。
