If you have to shout to be heard, the background noise is loud enough to cause hearing impairment. A large truck 5 yards away generates sound at about 90 decibels (dBs) and a jet engine 100 feet away generates sound at 130 dB. Sounds above 80 dB cause air vibrations big and powerful enough to damage the inner ear, especially if the sound continues for a long time. In the United States, laws regulate the maximum job noise exposure that is allowed, counting both the decibel level and length of exposure.
Major Industrial Health Issue:
According to the Centers for Disease Control, 22 million U.S. workers are exposed to hazardous occupational noise. America’s most common work-related illness is hearing loss .
- The mining sector has the highest prevalence of impairment (20 percent of people employed in mining had significant impairment).
- The construction industry is second (19 Percent of workers) and manufacturing is third.
- Close to one-fifth of workers in these industries have significant ear damage-based hearing impairment due to their work environments.
- Public sector workers (including emergency services) had the lowest rate of impairment (7 percent) which figure may be close to representing a baseline rate in the United States.
The CDC study estimated the impact of occupational hearing loss on the economy in the finding that
“Approximately 78 percent of the healthy years lost [to the economy] were attributable to mild or moderate hearing impairment.”
Secondary Effects:
Even mild hearing loss causes work impairments that are costly in terms of production and workplace behavior such as
- Difficulty understanding speech.
- Over-reaction to background noise.
- Degraded communication.
- Eventual cognitive decline and depression.
Noise acts through the ear but affects the central and autonomous nervous systems. When the sound stimulus passes a certain threshold it has pathological effects beyond just hearing loss. It affects concentration and ability to sleep. It has been known to increase the likelihood of anti-social behavior.
Undetected and unacknowledged hearing loss in the workplace are quickly misinterpreted by coworkers and supervisors. It may appear as
- Failure to heed alarms or telephone calls.
- Failure to understand instructions given on the phone with consequent patterns of inconsistency in following instructions.
- Loss of understanding of speech in groups.
- Failure to understand speech when the speaker is not seen.
- Loss of ability to understand whispers.
These failures in social communication caused by undetected hearing loss may pile up causing changes in the way the sufferer is perceived and his or her ability to carry on normal social relationships in the workplace.
Health Impacts:
Vibroacoustic disease (VAD) is a systemic pathology caused by excessive exposure to noise (especially low-frequency noise–that causes larger movements of the cochlear hair).
- The disorder impinges on the entire body, especially the heart and blood vessels.
- Just as the sound energy destroys filaments in the ear, the sound vibrations damage fine organs like pericardial filaments in the respiratory tract.
- VAD-related damage has been found in fine structures throughout the body.
Best Practices:
Under the Occupational Health and Safety Act (OHSA) health and safety officers at industrial worksites are obligated to conduct hearing tests if they find noise zones in the workplace. Failure to conduct testing makes them liable for fines. These tests must be conducted by someone trained in audiology. Employers are obligated to inform any employees who are working in a noise zone, and instruct them about the precautions they will be obligated to take.
Standard best practices suggest the following:
- New employees must be tested within 30 days of starting their employment to establish a baseline to assess impairment.
- Baseline hearing tests must be performed on all employees exposed to noise zones.
- All audiograms must be entered in the employment records to document the testing for the Labor Department inspectors.
If you suffer injury on the job in Minnesota, the Law Office of Joshua Borken is your law office. Please contact us to find out more.