Protecting hearing in a military environment.

In the Army, as in civil industry, there are many noise sources where the noise can not be reduced to safe levels except by use of hearing protectors, such as ear plugs, ear muffs or noise-excluding helmets. This paper shows how the effectiveness of hearing protectors can be determined for both continuous and impulse (gunfire) noise. It is shown that the results are in most cases in agreement with results for the real-ear attenuation at threshold method; the reasons for the exceptions are discussed. Hearing protection is often unpopular with users; reasons for this include discomfort, difficulty in speech communication, and incompatibility with other headgear. The degree of protection in practical usage is often much less than that measured in the laboratory. Possible solutions to these problems are described.