Most of us take our sense of hearing for granted; we assume that we hear what everyone else hears. Noise is one of the largest across-the-board health risks in construction. Loss of hearing may not be realized until the end of a rock concert and the ringing from your ears doesn't go away for a significant period of time. Noise comes not only from the tasks individual workers are performing, but also from high ambient levels at many sites. In addition to impairing the quality of life on and off the job, hearing loss puts workers at high risk for injuries. Sites become hazardous when any employee is unable to hear.
Hearing loss is usually a chronic affect, although at high levels loud noise can cause acute affects, noise levels are often not thought about as hazardous. It doesn't annoy us like smelling ammonia. In fact, many of use turn to loud noise to drown out other noise pollution.
According to Mark Stephenson, audiologist with NIOSH, the typical construction worker already has, or is acquiring, a debilitating, and permanent hearing loss. "The average carpenter, by the time he's 25, has 50-year-old ears. The sad thing is, no construction worker needs to lose his hearing. Noise-induced hearing loss is 100 percent preventable," Stephenson said.
Our ability to hear when we want to is taken for granted at work and at home. Employers often reduce the amount of noise in the workplace by enclosing or muffling loud machinery, but it's almost impossible to eliminate it completely. Another option to reduce exposure is for employers to rotate employees in and out of certain jobs.
Whatever the length of time you work in an area with high noise levels, you are likely required to wear a type of hearing protection. Most people consider this an inconvenience. However the more one understands the risks of damaging one's hearing, the more likely one is to take the steps needed to prevent it.
The critical sound level when hearing protection should be worn is 85 decibels (dBA), established for an 8-hour time weighted average. The louder and longer your exposure, whether at work, at home, or during recreation, the more likely your hearing will be damaged. If you want to have a sense of "how loud is loud," the following examples, along with their decibel rating, will give you an idea:
20 a faint whisper
30 - 40 quiet pleasant sounds, a bird chirping
40 - 50 quiet to normal office sounds
50 - 60 normal conversation
70 - 90 heavy machinery, electric motors, garbage disposal, city traffic
100 - 120 jack hammer, power saw, motorcycle, lawn mower, rock music
140+ nearly jet engine, gun shot (this level causes pain)
Many disposable or reusable plugs are available and most reduce noise by about 20 to 30 decibels. The noise reduction rating (NRR) is usually marked on the package, or on the box if in bulk. However, since the NRR is established in a laboratory with perfectly fitted plugs, experts recommend that the true rating is generally about seven decibels less than indicated. Hearing protectors of the ear muff type are usually closer to the actual NRR.
Wear your hearing protection!