Imagine living in a world without sound. What would it be like to never hear the rustling of leaves, the rumbling of the ocean, the chirping of a bird, or the cry of a baby? For most of us this would be hard to imagine but unfortunately many of us will someday be able to answer this question first hand if steps are not taken now to prevent Cumulative Hearing Loss.
Technically speaking, the human ear is capable of hearing very low pitched sounds like the lowest bass note of a piano ( around 20 Hertz) to very high pitched sounds of 20,000 Hertz. Very young children usually have the ability to hear sounds at the very lowest and highest ends of the scale. Through the normal aging process it is natural to begin to lose the ability to hear very high pitched sounds. This type of hearing loss (6000 Hertz and higher) is considered natural because it happens to almost all of us as the years roll on and is referred to as presbycusis. At the very worst, presbycusis may muffle out some of the shrillness of the world around us.
The pitch of human speech ranges from 300 to 4,000 Hertz. Failure to hear sounds in this range could seriously impair a person's day to day life by making it difficult to understand ordinary conversation. For most of us, this type of hearing loss is easy to prevent if we understand how it usually occurs. Cumulative hearing loss is usually the result of frequent exposure to loud noises. Well just how loud is loud? The intensity or "loudness" of sound is measured in units called decibels. The Occupational Safety and Health Administration (OSHA) tells us that individuals who are exposed to noises above 90 decibels (dB) on an average of 8 hours a day for five days a week can suffer permanent hearing loss in the low frequency ranges. The longer and more frequently this occurs the more serious the problem. The 90 dB limit is referred to as the PERMISSIBLE EXPOSURE LEVEL or PEL. The PEL can be defined as the maximum intensity of noise that an individual can be exposed to 8 hours a day five days a week without suffering any adverse effects based on a Time Weighted Average. A simple way to describe just how loud a decibel is would be to give you something to compare it with. Look at the chart below----this might help.
Noise Decibels (dB)
Whisper 20Quiet House 30
Average Home 50
Dishwasher 65
Vacuum Cleaner 75
Alarm Clock 80
Noisy Street 85
Subway Train 88
20 Ton Truck 90
Newspaper Printing Press 95
Power Mower 105
Bulldozer 110
Jackhammer 110
Pneumatic Chipper 125
Jet Engine 140
OSHA requires that employers initiate a Hearing Conservation Program which requires employees to wear hearing protection and to have yearly audiograms performed if they have the potential to be exposed to noises of 90 dB or higher. In fact an ACTION LEVEL of 85 dB has been established as the level at which employers need to begin initiating steps to monitor employee noise exposure and to begin steps to reduce noise levels in the workplace. The Department of Environmental and Occupational Health and Safety (EOHS) has just recently completed the University's Hearing Conversation Program. As part of this program, employees that have occupational exposures to noises that exceed the 85 dB action level have had base-line audiograms performed. In addition, these employees will be required to have annual audiograms performed, at the University's expense, to assure that the University's program is working. Surveys have been performed all around campus to determine what jobs and what equipment require hearing protection to be worn. If you feel that you are working in an environment, or with equipment that might require that you be part of the University's Hearing Program, please call EOHS at Extension 3700 so that we may survey your work environment.
Exactly how does one eliminate the hazards associated with high noise levels. Ideally the first step should be to try to eliminate or reduce the noise at its source. This can be done in a number of ways such as replacing noisy equipment with equipment that is designed to run quieter. Sound enclosure and noise deadening devices can also be used to reduce the level of noise that employees are exposed to. Minimizing the time that employees are exposed to loud noises is also an acceptable method. Lastly, if none of the above are possible, then employees can be fitted with hearing protection such as ear muffs or ear plugs. It is important to emphasize that sound industrial hygiene practice dictates that devices like these, referred to as personal protective equipment (PPE), should be used as a last resort only after all other methods to eliminate the noise have been exhausted.
It is important that employees who are part of Youngstown State University's Hearing Conservation Program follow the procedures, that have been established by the University to protect their hearing. This includes wearing hearing protection when working with equipment or at jobs where noise levels are at or exceed the PEL. The University will make every attempt to protect your hearing on the job. The University can and will takes steps to protect your hearing on the job, but what happens off the job is another matter and entirely up to you. Attempts to protect your hearing at work becomes futile if the same hearing precautions are not taken when you are off the job. Even though you may not be exposed to excessive noises at work, your home environment may be quite another story. Be aware of the noises around you away from work and use the same precautions that are encouraged on the job. Remember that protecting your hearing is just as crucial off the job. In fact, for some individuals there is more of a potential to be exposed to excessive noises at home.
Here are some important points to consider when thinking about protecting your hearing away from your job.
Many individuals play their radios at levels loud enough to harm their hearing and anyone else that is in earshot.
Power equipment used in home workshops can produce noise levels that can cause hearing damage.
Some garden tractors and lawn mowers can produce noise in excess of OSHA's PEL.
Sounds produced by gunshot during hunting or practicing at indoor or outdoor shooting ranges can cause sudden hearing loss.
Decibel levels at rock concerts can be louder than those produced by a jackhammer or chain saw.
Many headsets will broadcast sound at levels of 115 decibels. This is equal to standing 100 feet from a jet at takeoff.
Noise levels at auto or motorcycle races can be deafening.
Any employee who has any questions or concerns about the use of hearing protection, whether it be related to work or the home environment is urged to contact EOHS for more information.
Play it safe--protect your hearing at all cost. It's a precious gift that should not be taken for granted.
