There is no question that construction sites are loud. Between the bulldozers rumbling across the ground, jackhammers breaking through concrete or saws cutting through metals and woods, noise is almost impossible to avoid. According to the National Institute for Occupational Safety and Health (NIOSH), the construction industry has the second highest risk for developing hearing loss from noise exposure of any industry. NIOSH also reports that 23 percent of workers in the U.S. experience hearing difficulty after being exposed to noise on the job. Another 15 percent have experienced tinnitus, the sensation of ringing or buzzing in one or both ears.
Construction workers encounter multiple hazards on the job, but, more often than not, noise is not considered as critical as some of the other present dangers. Hearing loss is typically gradual and not immediately noticeable, unlike other potential workplace injuries such as cuts, head wounds and broken bones. Hearing damage is preventable but cannot be undone. There is no surgery or cure for noise-induced hearing loss. Repeated exposure to high noise levels, such as working near machinery or operating heavy equipment, can lead to permeant hearing loss or tinnitus. Ask any construction worker who now has difficulty hearing what they should have done differently, and the majority will agree they should have worn hearing protection before the damage was done.
How Loud is Too Loud?
The loudness of sound is measured in units called decibels (dB). The decibel is measured on a logarithmic scale. This means that a small change in the number of decibels results in a large change in the amount of noise and the potential damage to a person’s hearing.
The higher the decibel level, the louder the noise is and the shorter the amount of time it takes for hearing loss to occur. A casual conversation between two individuals can generate between 50-60 dB of sound while a jet engine taking off can measure around 140 dB. The average construction site has a decibel level between 80-90 dB, but many common tasks found on the jobsite can be well above that. For example, a forklift produces about 93 dB and a jackhammer more than 100 dB. The CDC estimates that levels above 70 dB over a prolonged period may start to damage hearing and levels above 120 dB could cause immediate harm.
The decibel level, the distance between a person and the source of the noise, and the amount of time they are exposed can all result in a risk for hearing loss. OSHA has set a legal limit on the amount of noise someone can be exposed to in the workplace. These limits are calculated based on a worker’s time-weighted average throughout an eight-hour day. OSHA’s permissible exposure limit (PEL) is 90 dB for all workers for an eight-hour day. The OSHA standard uses a 5 dB exchange rate, meaning if the decibel level is increased by 5 dB, the amount of time a person can be exposed to that level is reduced by 50 percent. For example, a construction worker can be exposed to 90 dB of noise for eight hours but 95 dB for only four hours.
Workplace noise is sometimes referred to as a “stealth, long-term hazard” because hearing loss occurs slowly, in a painless, gradual process. In a study done by the CDC, 51 percent of construction workers have been exposed to hazardous noise levels. Of those workers, 31 percent reported not wearing hearing protection. High decibel levels damage the cells and membranes in the inner ear. Repeated exposure will overwork those cells, causing them to die and result in hearing loss that surgery cannot fix. While hearing aids may help, they do not restore hearing back to normal. NIOSH estimates that 30 million workers are exposed to noise levels high enough to cause irreversible hearing loss.
When decibel levels are at or above 85 dB over an average of eight working hours, OSHA’s Noise Standard requires employers to make hearing protection available to all employees and to implement a hearing conservation program. According to OSHA, these programs “strive to prevent initial occupational hearing loss, preserve and protect remaining hearing and equip workers with the knowledge and hearing protection devices necessary to safeguard themselves.” With the decrease of even a few decibels, the risk for noise-induced hearing loss is reduced. OSHA recommends three methods for controlling decibel levels in order to lessen the hazardous noise exposure and prevent hearing loss:
Engineering Controls. With engineering controls modifying or replacing equipment, you can make physical changes at either the source of the noise or along the path of noise transmission to reduce the decibel level a worker experiences. This could be as simple as lubricating a squeaking bearing or as vigilant as completely enclosing and isolating the noise source.
Administrative Controls. These changes in the workplace can reduce or eliminate the worker’s exposure to the noise, such as limiting the amount of time a person spends at the noise source or even providing a quiet environment to give time for a worker’s ears to rest between exposures.
Hearing Protection Devices (HPDs). HPDs are active or passive ear protection devices worn in or over the ears, such as ear plugs or ear muffs, to reduce the decibel exposure and protect against hearing loss
One Size Does Not Fit All
Engineering and administrative controls can take time or are not feasible to implement, making HPDs a necessity to prevent hearing damage. However, historically, HPDs have been less than desirable for a construction worker to wear. Comfort and convenience are common complaints. Ear plugs can easily get misplaced or dirty and ear muffs can be difficult to wear with a hard hat. PPE has seen little innovation through the years, but some companies, such as Milwaukee Tool, are working to challenge the status quo.
According to company research, comfort and accessibility are two areas that hearing protection could improve on. Ear plugs are often considered an easy choice for construction workers because they are disposable and do not impact other PPE they may also have to wear.
There are three critical things to consider when selecting the proper ear plug. The first is the size of the ear canal opening to determine which size of ear plug is best. Next is to check the shape of the ear canal as different materials may be more comfortable depending on the user’s ear canal shape.
Lastly, determine how easy it is to insert the ear plug. To ensure those wearing hearing protection have sufficiently reduced the amount of noise entering their ears, OSHA rates ear plugs using a Noise Reduction Rating (NRR). This unit of measurement is used to determine the effectiveness of hearing protection to decrease sound exposure. The higher the NRR number associated with a hearing protector, the greater the potential for noise reduction. Milwaukee’s Banded Ear Plugs are rated to an NRR of 26 dB. Its Ear Plugs are NRR 32 and its Reusable Corded Ear Plugs are NRR 26.
The Last Word
Hearing loss is one of the most common work-related illnesses in the United States. Because hearing loss occurs over time, it can easily go undetected until it is too late, and the irreversible damage to the ear has already been done. The tasks needed to get done on a jobsite can produce hazardous decibel levels, but taking control of the noise on the jobsite and proper use of HPDs, exposure to these noise levels can decrease a construction worker’s risk of noise-induced hearing loss.