Mining for silence

According to an engineer from Cooper-Standard Automotive, active noise control is finally making the transition from marketing hype to viable product.

In the 1999 update of the Mine Safety and Health Administration (MSHA) noise standard, MSHA estimated that in the current state, 13% of U.S. miners (about 37,000) will suffer a significant loss of hearing. This estimate has resulted in a multi-tiered approach to assess and address the noise exposure levels for all mine personnel. These tiers are defined in terms of a lower “action level,” above which some manner of exposure intervention occurs, and “permissible exposure level,” above which more severe penalties can occur.

Mine workers are exposed to a variety of noise sources, each with a unique noise signature that combines to form the composite disturbance. Mine machinery and vehicle engineers are tasked with the job of using noise-control techniques to meet regulatory levels of exposure that are continually reduced. The latest MSHA update explicitly requires mine operators to use all feasible engineering and administrative controls to reduce miners' noise exposure to permissible exposure levels.