"Is it really that loud?" Many of us have been taken aback by warnings from our devices that urge us to turn down our headphones even though the volume is hardly ear-splitting.
But don't be surprised—noise doesn’t have to be piercingly loud to cause permanent hearing damage. According to the Centers for Disease Control and Prevention (CDC), over a prolonged time period, a person's hearing can be harmed by sounds over 70 decibels. That's about as loud as a washing machine or a dishwasher. Louder sounds cause damage more quickly.
When your headphones can be hazardously loud without your realizing it, it's easy to understand how noise hazards in the workplace can go unnoticed, too. According to a study published by the Journal of the Acoustical Society of America, approximately 22 million workers are exposed to occupational noise hazards in their jobs today, and one-third of workers who have a history of occupational noise exposure show measurable hearing damage.
Who's at Risk?
Sometimes noise hazards are obvious, but it's not just jackhammer operators who are at risk. High percentages of workers in these five fields face workplace noise hazards:
- Manufacturing: Approximately 5.7 million factory workers (about 46 percent of the manufacturing workforce) are exposed to dangerous sound levels at work. Almost one-third of exposed workers report not wearing hearing protection, leaving one in five with material hearing impairment.
- Agriculture: The noise inside a tractor cab can reach 92 decibels, and equipment like grain dryers and combines can top 100 decibels. In addition to these noise hazards, exposure to some pesticides can increase the risk of hearing loss among agricultural workers.
- Transportation and Warehousing: Forklifts and pallet trucks are loud, frequently emitting dangerous levels of noise when a load shifts against the forks or the backup alarm sounds. Railroad workers are at high risk of hearing loss, with 35 percent of rail workers reporting hearing difficulty. Truck drivers live in high-noise environments—an unmuffled “Jake Brake” can reach 101 decibels, as loud as a chainsaw.
- Maintenance and Repair: In addition to using loud tools like pneumatic wrenches and grinders, maintenance and repair workers often do their jobs in noisy environments like factories and construction sites. While over half of maintenance and repair workers are exposed to dangerous noise levels, 43 percent of exposed workers report not wearing hearing protection on the job, according to the Journal of Acoustical Society of America study.
- Construction: More than half of the construction workers have been exposed to noise hazards, but only 52 percent of exposed workers regularly wear hearing protection. One-quarter of construction workers already suffer from material hearing impairment.
What's the OSHA Perspective?
OSHA’s Occupational Noise Exposure Standard (29 Code of Federal Regulations (CFR) 1910.95) identifies 90 decibels in an eight-hour time-weighted average (TWA) as the absolute "safe" level of noise exposure.
The 90-decibel concentration is the OSHA permissible exposure limit (PEL). Any eight-hour TWA exceeding 90 decibels requires the employer to use control measures to reduce the exposure to 90 decibels or below.
In addition to the 90-decibel PEL, OSHA also recognizes an 85-decibel TWA as its action level. While employee exposure to the action level does not force an employer to take measures to reduce noise exposure, it does require the employer to establish a hearing conservation program.
A hearing conservation program mandates that the employer conduct noise exposure monitoring, perform audiometric testing on employees, provide hearing protection to employees who request it, conduct employee training and retain records of the those activities.
What Can You Do?
Hearing protection is important, but reducing noise at the source is the best solution. And noise reduction doesn't have to be extreme to be effective. In fact, decreasing noise levels by 5 to 10 decibels is all that is needed to bring 99% of workplaces into compliance with OSHA regulations.
An easy first step is buying quiet equipment. Quieter fans, cutting tools and electric motors can help reduce the costs of your hearing conservation program. Every decibel of noise reduction is projected to save $100 in long-term costs associated with noise hazards.
Here are five more innovative strategies that have worked in the real world, as recognized by the NIOSH-initiated Safe in Sound Award, which recognizes excellence in hearing protection.
Hard caster wheels rolling on concrete and metal surfaces can generate sounds near 90 decibels. Switching to softer nylon or neoprene wheels can yield reductions of up to 16 decibels, bringing noise levels below a safe threshold.
Shrouding, Isolation and Relocation
Shielding and separating workers from noisy equipment can drastically reduce noise exposure. For example, at an abrasives manufacturing facility in Alexandria, Virginia, a combination of acoustical shrouds and the relocation of noisy equipment resulted in a 12-to-14-decibel reduction in sound levels throughout the plant. Prior to the plant’s noise reduction initiative, 98 percent of workers were included in a hearing conservation program. Afterwards, only 2 percent of workers were at risk from hazardous noise levels.
Placing loud equipment inside sound-deadening chambers can dramatically reduce noise levels. For example, at one manufacturing facility, the testing process for emergency sirens is inherently noisy—the equipment is designed to emit warning tones of 110 decibels or more. But by moving the testing procedure inside sound-deadening enclosures, the plant was able to remove 77 percent of employees from its hearing conservation program.
Video technology can allow workers to operate noisy equipment from a safe distance. A materials company installed remote controls and video monitoring on its fleet of concrete trucks, allowing operators to control the truck’s concrete chute from the truck’s acoustically shielded cab. Remote operation reduced some drivers’ noise exposure “severity ratio” by over 50 percent.
Not all alarms need to be an ear-splitting 95 decibels. For example, one technology facility replaced its transfer carts’ pressure sensor alarms with flashing visual indicators, eliminating a noise hazard from the production floor.