Engineering Controls to Reduce Noise

Exposures and Controls

Exposure to Noise is measured in units of sound pressure levels called decibels, using an A-weighted sound levels (dBA). There are several ways to control and reduce worker exposure to noise in a workplace where exposure has been shown to be excessive.

Engineering controls involve modifying or replacing equipment, or making related physical changes at the noise source or along the transmission path to reduce the noise level at the worker’s ear. Examples of inexpensive, effective engineering controls:

• Choose low-noise tools and machinery
• Maintain and lubricate machinery and equipment (e.g., oil bearings)
• Place a barrier between the noise source and employee (e.g., sound walls or curtains)
• Enclose or isolate the noise source.

Administrative controls are changes in the workplace or schedule that reduce or eliminate the worker exposure to noise. Examples:

• Operate noisy machines during shifts when fewer people are exposed
• Limit the amount of time a person spends at a noise source;
• Provide quiet areas where workers can gain relief from hazardous noise sources; and
• Control noise exposure through distance is often an effective, yet simple and inexpensive administrative control. Specifically, for every doubling of the distance between the source of noise and the worker, the noise is decreased by 6 dBA.