- ISHN GLOBAL
- EHS RESEARCH
Millions of workers are subjected to countless sources of noise every day ranging from construction to manufacturing to utility jobs. Most of these mundane noises are heard at a safe level and do not affect hearing… but when workers are exposed to noise that is harmful, these seemingly unavoidable sounds on the job could be the cause of a worker to never hear again. That is because sounds simply are too loud or are loud for a long enough time to damage the sensitive structures in the inner ear. This can lead to noise-induced hearing loss — and many of these harmful noises can be found in the workplace.
Every year, about 30 million people are occupationally exposed to hazardous noise in the United States, rendering occupational hearing loss one of the most common occupational concerns for workers in agriculture, mining, construction, manufacturing, utilities, transportation, and the military.
Since 2004, more than 125,000 workers have suffered significant permanent hearing loss, according to the Bureau of Labor Statistics, with additional reports in 2009 alone of more than 21,000 hearing loss cases.
Sound is measured on the decibel scale, and an increase of 10 means that a sound is 10 times more intense, or powerful; to your ears, it sounds twice as loud. To put hazardous noises in perspective, the chart above provides a list of common sources of noise and the OSHA level for a hearing conservation program.
There is no cure for permanent hearing loss, which means it is critical to prevent exposure to excessive workplace noise. To do this, two types of noise controls, engineering and administrative, are the first line of defense and 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 and noise-related annoyance is reduced. There are several ways to control and reduce worker exposure to noise in a workplace.
For most noise sources, engineering controls are available and technologically feasible. These types of noise controls involve making physical changes at the noise source, such as modifying or replacing equipment, or making changes along the transmission path to ensure the worker is not overexposed. Applying a relatively simple engineering noise control in some instances could reduce the noise hazard to the extent that further requirements of the OSHA Noise standards are not necessary. According to OSHA, here are some examples of inexpensive, effective engineering controls:
- 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
The other type of noise control, administrative, creates changes in the workplace through distance and separation from the noise source that reduce or eliminate the worker’s exposure. This is often an effective, yet simple and inexpensive administrative control that may be applicable when workers are present but are not actually working with a noise source or equipment. In open space, for every doubling of the distance between the source of noise and the worker, the noise is decreased by 6 dBA.
- 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, such as a soundproof room
- Restricting worker presence to a suitable distance away from noisy equipment
- Federal and state laws set legal limits on companies whose workers are exposed to high noise levels in the workplace, permitting shorter durations of exposure as the hazardous noise level rises.
Hearing conservation programs
Many state OSHA programs require employers to have a workplace hearing conservation program when workers are exposed to noise levels that meet or exceed 85 decibels over an average period of eight hours. Hearing conservation programs are imperative in protecting workers to prevent hearing loss and should contain provisions for identifying and evaluating high noise exposures, controlling and reducing noises in the workplace, and ways to monitor workers’ hearing. The required elements of a Hearing Loss Prevention program are:
Monitoring — Noise exposure levels must be measured wherever they may reasonably be expected to be above an eight hour time weighted average of 85 dBA.
Noise Controls — must be evaluated and implemented wherever employee exposures are at or above an eight hour time weighted average of 90 dBA.
Audiometric Testing Program — all employees with an eight-hour time-weighted exposure of 85 dBA or above must be included in an audiometric testing program. A baseline audiogram must be established within the first six months of exposure and annual testing and evaluation must be done.
Hearing Protection — The employer must provide hearing protection for all employees who have an eight-hour time-weighted exposure of 85 dBA or above, who have any continuous exposure at or above 115 dBA, or who have an exposure to any impulse noise levels above 140 dB.
Training — Employers must provide training to all employees exposed to noise at or above an eight-hour time-weighted average of 85 dBA. Training must include the following items: the effects of noise on hearing, information on hearing protectors and their use, information on audiometric testing and its purpose, and the employees’ right to access to records. The employer must maintain a written description of the training program.
When engineering or administrative controls are not feasible, hearing protection devices (HPDs), such as earmuffs and plugs, are considered an acceptable option to control exposures to noise, as well as to use when a worker’s hearing tests indicate significant hearing damage.
Despite these efforts, an estimated 15 percent of workers will develop hearing loss this year from exposure to noise levels of 85 dBA or higher, according to the National Institute for Occupational Safety and Health.
Don’t become a part of this statistic. Find out for yourself if you are at risk for hearing loss at your job. A good rule of thumb: if you have to shout to be heard by a co-worker who is arm’s length away, or if you hear ringing or humming in your ears when you leave work, these are warning signs that your workplace has excessive noise levels — and some sound advice would be to prevent the loss of your hearing.
1. “Noise Exposure - Hearing Loss.” Health and Safety Topics. Washington State Department of Labor & Industries, n.d. Web. 7 Aug. 2012. <http://www.lni.wa.gov/Safety/Topics/AtoZ/NoiseHearing/default.asp>.
2. “Noise-Induced Hearing Loss.” National Institute on Deafness and Other Communication Disorders. National Institutes of Health, Oct. 2008. Web. 10 Aug. 2012. <http://www.nidcd.nih.gov/health/hearing/pages/noise.aspx>.
3. “Occupational Noise Exposure.” Safety and Health Topics. United States Department of Labor, n.d. Web. 7 Aug. 2012. <http://www.osha.gov/SLTC/noisehearingconservation/>.
4. Rabinowitz, Peter M., M.D., M.P.H. “Noise-Induced Hearing Loss.” AAFP. American Academy of Family Physicians., 1 May 2000. Web. 8 Aug. 2012. <http://www.aafp.org/afp/2000/0501/p2749.html>.