Noise is a significant physical hazard. Over time, workers in environments with high sound levels can experience significant hearing loss. When workers experience continuous or near-continuous noise in the workplace, even lower sound levels can cause hearing impairment.

Additionally, infra-sound and ultra-sound which cannot be normally heard can still have adverse effects and must be monitored and controlled in order to minimize risks of hearing impairment.

Limits on noise exposure are given in terms of sound pressure levels and durations of exposure: longer exposure times require lower sound levels. For most jurisdictions, the sound level over an 8-hour shift should not exceed 83-85 dBA. However, noise levels must never exceed 140 dBA.

Many jurisdictions, including OSHA in the United States, require that workers in noisy areas be periodically tested as a precaution against hearing loss. Additionally, if noise levels in a workplace exceed noise limits, a hearing conservation program must be implemented including routine monitoring, worker education, and exposure control including supplying workers with hearing protection equipment.

Noise can be reduced by proper use of personal hearing protection including ear plugs and ear muffs. Protection must be selected that has adequate noise reduction ratings (NRR) in order to reduce exposure to the safe levels.

Noise can be also reduced by installing equipment and systems that have been engineered, designed, and built to operate quietly; by enclosing or shielding noisy equipment; by making certain that equipment is in good repair and properly maintained with all worn or unbalanced parts replaced; by mounting noisy equipment on special mounts to reduce vibration; and by installing silencers, mufflers, or baffles.

Substituting quiet work methods for noisy ones is another significant way to reduce noise, for example, welding parts rather than riveting them. Also, treating floors, ceilings, and walls with acoustical material can reduce reflected or reverberant noise. In addition, erecting sound barriers at adjacent work stations around noisy operations will reduce worker exposure to noise generated at adjacent work stations.

It is also possible to reduce noise exposure by increasing the distance between the source and the receiver, by isolating workers in acoustical booths, limiting workers' exposure time to noise, and by providing hearing protection.