The current MSHA regulation dictates the use of engineering and administrative controls to reduce exposures to hazardous noise levels. This module will provide a basic introduction into various controls as well as provide information regarding personal protective equipment for noise.
The following types of engineering controls can provide varied decibel reduction when applied to the correct equipment and in the proper manner: equipment substitution, changing equipment operating conditions (i.e., reduce velocity, reduce driving force, etc.), equipment noise enclosures, personnel noise enclosures, shields/barriers, sound absorption, vibration dampening materials, lagging, and mufflers. The feasibility of the controls should be considered when designing noise engineering controls.
The following types of administrative controls can provide varied decibel reduction when consistently applied: limiting worker time in the noise area or operation and procedures for equipment operation that reduces noise levels (e.g., control of compresses air pressure and electrical current settings during air-arc gouging).
Personal Protective Equipment
While hearing protection is not to be used in lieu of engineering or administrative controls the use of hearing protection is widespread and usually long-term. It is important to ensure personnel who are required to wear hearing protection do so consistently and correctly. A variety of studies have shown that the noise-reduction rating on the hearing protection is seldom attained by workers who are not adequately trained on how to insert and use hearing protection. Fit-testing devices are now available to allow the user to see the type of fit they are receiving with the ear plugs they are using. This tool has been shown to dramatically increase correct hearing protector application and reduce noise exposure.