There are two primary types of noise which are produced by any pile hammer. The first is impact noise produced by the ram striking the pile. The second type of noise is produced by the operating steam or air as it is exhausted from the cylinder. In both cases, depending upon hammer size, it is possible to produce noise levels which are potentially damaging to the auditory mechanism in the ear.
At present, there are not too many practical ways to reduce these noise levels. In the case of impact noise, cushion material can be used to reduce the noise levels as well as modify the impulse duration as required by soil type and piling composition. The exhaust noise can also be reduced through the use of an exhaust muffler. However, if it is impractical to muffle the exhaust, there are other alternatives which will provide construction personnel with adequate hearing protection. Because sound intensity decreases rapidly as the distance from the hammer increases, simply keep all personnel as far from the hammer as is practical. Obviously, there are many other safety reasons why no one should be near the hammer when it is in use. However, if personnel cannot be stationed far enough from the hammer to adequately reduce the noise, earmuffs or earplugs should be used. If there is concern about the noise level at any job site, it is advisable to use a sound level meter to establish what abatement procedure is needed. It is obvious that the user must give more attention to the noise problem as ever more stringent environmental safety restrictions are imposed by government authorities. Refer to O.S.H.A. Standards 1910.95 and 1926.52, Occupational Noise.