职业安全与健康管理局噪音规定：合规途径

Occup Health Saf. 1979 Nov-Dec;48(8):52-4.

Personal ear protection is probably the most expensive and least fruitful approach when one considers the cost of plugs, tests, monitoring and record keeping.

当考虑到耳塞、测试、监测和记录保存的成本时，个人耳部防护可能是最昂贵且成效最小的方法。