Exposure to high levels of noise can cause permanent hearing loss. Neither surgery nor a hearing aid can help correct this type of hearing loss.
- Short term exposure to loud noise can also cause a temporary change in hearing (your ears may feel stuffed up) or a ringing in your ears (tinnitus).
- Repeated exposures to loud noise can lead to permanent tinnitus and/or hearing loss.
Noise-induced hearing loss limits your ability to hear high-frequency sounds, understand speech, and seriously impairs your ability to communicate. Noise may be a problem in your workplace if:
- You hear ringing or humming in your ears when you leave work.
- You have to shout to be heard by a coworker an arm’s length away.
- You experience temporary hearing loss when leaving work.
OSHA sets legal limits on noise exposure in the workplace. These limits are based on a worker’s time-weighted average over an 8-hour day (called an 8-Hour TWA). With noise, OSHA’s permissible exposure limit (PEL) is an average of 90 decibels (dBA) for all workers for an 8-hour day.
The OSHA standard uses a 5 dBA exchange rate. This means that when the noise level is increased by 5 dBA, the amount of time a person can be exposed to a certain noise level to receive the same dose is cut in half.
OSHA’s requirement to protect all workers in the general industry calls for employers to implement a Hearing Conservation Program where workers are exposed to a time-weighted average noise level (called the “action level”) of 8-Hour TWA of 85 dBA or higher. Hearing Conservation Programs require employers to measure noise levels, provide free annual hearing exams, free hearing protection, and training.
Reducing Noise Hazards
Noise controls are the first line of defense against excessive noise exposure. The use of these controls should aim to reduce the hazardous exposure to the point where the risk to hearing is eliminated or minimized. With the reduction of even a few decibels, the hazard to hearing is reduced, communication is improved, and noise-related annoyance is reduced. There are several ways to control and reduce worker exposure to noise in a workplace.
Engineering Controls: 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 include some of the following:
- Choose low-noise tools and machinery.
- Maintain and lubricate machinery and equipment.
- Place a barrier between the noise source and employee.
- Enclose or isolate the noise source.
Administrative Controls: These are changes in the workplace that reduce or eliminate worker exposure to noise. Examples include:
- Operating noisy machines during shifts when fewer people are exposed.
- Limiting the amount of time a person spends at a noise source.
- Providing quiet areas where workers can gain relief from hazardous noise sources.
- Restricting worker presence to a suitable distance away from noisy equipment.
Hearing protection devices (HPDs): Hearing personal protection equipment (PPE) such as earmuffs and plugs, are considered an acceptable but less desirable option to control exposures to noise. HPDs are generally used during the time necessary to implement engineering or administrative controls, when such controls are not feasible, or when worker’s hearing tests indicate significant hearing damage.