Noise and Occupational Hearing Loss
Noise and Hearing Loss
Loud noise can damage your hearing.
Noise is considered hazardous based on
- How loud the sound is
- How long the exposure lasts
- How often the exposure is repeated
Take Precautions When Noise Is 85 dBA or Higher
NIOSH established a recommended exposure limit (REL) of 85 A-weighted decibels (dBA) averaged over an eight-hour workday. Workers who are exposed to noise at or above the NIOSH REL are at risk of developing significant hearing loss over their working lifetime. Although the NIOSH REL is based on exposure for eight hours, everyone differs in their susceptibility to noise. You can check the noise level using a sound level meter.
NIOSH developed the NIOSH Sound Level Meter app to help measure sound levels with a mobile iOS device.
Sounds that are 85 dBA often require you to raise your voice to be heard by someone 3 feet away. Equipment that can produce noise levels around 85-90 dBA include:
- Printing presses
- Lawn mowers
- Vacuums
- Power tools
As noise reaches 95 dBA or more, you likely have to shout to be heard by someone 3 feet away. Exposures that average 95 dBA or higher include
- Bulldozers
- Ambulance sirens
- Chain saws
- Bars/nightclubs
- Large sporting events
This figure shows the relationship between exposure level and exposure duration under the NIOSH REL. As sounds become louder than 85 dBA, the length of a daily exposure must be reduced. For each 3 dBA increase in noise level, NIOSH recommends reducing the exposure duration by half. This is called the exchange rate. Similarly, if the daily exposure is longer than 8 hours, the allowable noise level is lower. To learn more, see Table 1-1 of the Occupational noise exposure; criteria for a recommended standard (cdc.gov).
In addition to having to raise your voice or shout to be heard, other signs that your workplace might be too noisy include
- Your ears ring or sounds seem dull or flat after leaving the noisy area.
- You need to turn up the car radio or your phone volume at the end of your shift compared to before your shift. You may also notice the radio volume feels too loud when you get in your car the following day.
Noise Exposure Is a Risk That Is Present in All Industries
Although hazardous noise most commonly occurs in industries such as mining, manufacturing, and construction, every industry has workers who are exposed to hazardous noise. For example, people working as janitors or administrative staff at noisy workplaces are also at risk for hearing loss.
How To Prevent Hazardous Noise Exposure in the Workplace
Employers, health and safety professionals, and workers can all take action to prevent hazardous noise exposure in the workplace. However, it is ultimately the employer’s responsibility to provide a safe work environment.
How Employers and Health and Safety Professionals Can Prevent or Reduce Hazardous Noise Exposure
The hierarchy of controls groups preventive actions by how well they may reduce or remove a workplace hazard. A summary of different prevention strategies based on the hierarchy of controls is provided below. You might need to use a combination of actions to maximize worker protection. Keep in mind all potential exposures should be considered. For example, isolating the noise does not reduce ototoxic chemical exposures in the area.
A summary of different prevention strategies based on the hierarchy of controls is provided below. The hierarchy of controls groups preventative actions by how well they may reduce or remove a workplace hazard. You might need to use a combination of actions to maximize worker protection. Keep in mind all potential exposures should be considered. For example, isolating the noise does not reduce ototoxic chemical exposures in the area.
Elimination: The most effective action is to remove the source of the noise.
Substitution: Another effective action is to use a quieter alternative, such as buying quieter equipment or tools.
For elimination and substitution, consider using Prevention through Design strategies to reduce noise exposures. Prevention through Design is an approach to proactively include prevention when designing work equipment, tools, operations, and spaces.
Engineering Controls: Engineering controls protect workers by removing hazardous conditions or by placing a barrier between the worker and the hazard. Noise controls can involve making physical changes to the equipment or to the workplace. Some examples include
- Isolating the noise source in an insulated room or enclosure.
- Placing a barrier between the noise source and the worker.
- Isolating the worker from the noise source in a room or booth (such as a sound wall or windows).
Administrative Controls: Administrative controls establish work practices that reduce the duration, frequency, or level of exposure to hazards. Some examples include
- Scheduling loud work when fewer workers are around.
- Giving workers shifts doing quieter tasks and breaks from loud work.
- Providing quiet and convenient break areas.
Administrative controls should not be used in a way that exposes more employees to noise.
Personal Protective Equipment (PPE): Provide workers with hearing protection devices when other approaches cannot reduce noise to a safe level. NIOSH recommends wearing hearing protection whenever noise levels exceed 85 dBA, regardless of how long the sound lasts. Hearing protection can be quite effective when chosen correctly and used consistently.
See innovative examples of hearing loss prevention from the Safe-in-Sound Excellence in Hearing Loss Prevention Awards™
How Workers Can Prevent or Reduce Hazardous Noise Exposure
If you work in a noisy environment, take the following actions to help protect yourself:
- Try to take a break from the noisy activity or reduce your time in noisy areas.
- Keep the volume low if you are listening to the radio or a personal music device and only listen in areas that are not noisy.
- Always wear hearing protection in noisy areas.
- Wear your hearing protection correctly (follow manufacturer instructions for proper use).
You can request assistance from NIOSH. Management, unions, or workers can request a NIOSH Health Hazard Evaluation to learn whether hearing hazards are present in the workplace and get recommendations to reduce hazards and prevent occupational hearing loss. You can also contact CDC-INFO with questions or email the NIOSH hearing loss prevention team at NIOSHNoiseResearch@cdc.gov.