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引言典型选煤厂中的噪声级往往在90dBA以上,有时还超过100dB(A)。因为选煤厂工人在每天上班的大部分时间暴露于这些噪声级中,所以这些工人的噪声暴露量往往会超过现行的美国联邦噪声条例所容许的限制值。认识到噪声对选煤厂中工人听力的潜在危害,矿业局提出了对选煤厂噪声控制技术进行研究。矿业局的早期研究工作大多是以现有选煤厂的噪声控制为目标,力量集中在鉴别现有选煤厂主要的噪声问题和评价可改型处理的一些噪声控制方法上,例如弹性的筛板、
INTRODUCTION Noise levels in a typical coal preparation plant often exceed 90 dBA, sometimes exceeding 100 dB (A). Because coal-preparation plant workers are exposed to these levels of noise most of the day, their exposure to noise is often outweighed by the current federal federal noise regulations. Recognizing the potential hazards of noise to workers’ hearing in the coal preparation plant, the Bureau of Mines proposed a study of the noise control techniques at the coal preparation plant. Much of the early research work undertaken by the Bureau focused on noise control at existing coal preparation plants and focused on identifying the major noise problems of existing coal preparation plants and evaluating some noise control methods that could be retrofitted, such as flexible screens board,