You rarely hear the saying, “It's so quiet, you can hear a pin drop” anymore. Perhaps that's because it's rarely so quiet — not at home, not at work, not even in recreational areas such as our national parks. We are surrounded by sound. More specifically, we are surrounded by noise.
“Noise” is loosely defined as annoying sounds, but one person's sound may be another person’s noise. Loudness, which is the sound power level, becomes ten times higher for each ten decibels increase in sound levels. To better understand this, consider that a whisper registers approximately 30 dB and normal conversation about 50 to 60 dB, while a ringing phone may be 80 dB and a power mower 90.
Noise may not just be annoying; at high intensity it can be damaging. Our ears were not meant to endure a constant hail of loud sounds. As a result, millions of Americans suffer from noise-induced hearing loss, or NIHL.
A single, very loud sound (such as an explosion or gunshot) can cause NIHL, but most people get it from regular exposure to sounds of 80 dB and above. Whether noise is encountered on the job or in the community, most people are at risk for NIHL if they don’t take precautions. The occupational health and safety professionals at AIHA believe that noise exposure is a growing issue in our communities and workplaces.
Why Worry about Hearing Conservation?
Most people suffer some loss of hearing as they age, but prolonged exposure to noise needlessly accelerates the process. Of the 28 million Americans who suffer some degree of hearing loss, nearly one-third have been affected, at least in part, by noise.
Loss of hearing has an impact on every level of our lives: in the workplace, among our family and friends, and at leisure. And despite the increase in e-mail for communication, the vast majority of our interactions are in person or on the phone. You may experience stress if you are constantly asking people to repeat themselves or know that you are missing important pieces of information. Moreover, straining to hear the dialogue in a movie theater or the high notes of a violin concerto, for example, diminishes the impact of the experience.
Researchers also have discovered that NIHL makes it difficult to experience and enjoy not only sound but silence as well. Millions of Americans suffer from ringing in the ears, known as tinnitus. People with tinnitus hear sounds that are only in their own ears—ringing, whistling, buzzing, or clicking, for example. These phantom sounds can become distressing, insofar as in many cases, they never go away. While there are several causes of tinnitus, NIHL has been identified as one of the most common culprits.
Tinnitus is only one of the symptoms of NIHL. Other symptoms include a gradual decrease in sound or a growing distortion, particularly of speech comprehension. Because it comes on slowly, a person with NIHL may not be aware of the impairment at first. He or she may even be unconsciously compensating for the loss by reading lips or turning up the radio or television volume.
Finally, unlike many injuries or illnesses, hearing loss may be permanent and irreversible. There are two types of noise-induced hearing loss, a temporary threshold shift (temporary loss of hearing) and a permanent threshold shift (a shift in the person’s ability to hear soft sounds). The hair cells in the inner ear can be bent down by low amounts of noise, but if the noise is of a long duration or extremely loud, these hair cells con be broken off and destroyed. Once gone, they are gone forever. Recent research has now shown that even without permanent hearing loss, some bundle branches of the auditory nerve can be lost forever. So even temporary threshold shifts can cause permanent damage to the ear’s nervous system.
When You Should Worry About Hearing Loss
Only a medical professional such as an otolaryngologist (ear-nose-throat specialist) or an audiologist can make the final diagnosis of diminished hearing, but there are several warning signs. According to the National Institute on Deafness and Other Communications Disorders, you may be suffering from hearing loss if you experience three or more of the following symptoms:
You have problems hearing over the telephone.
You have trouble following the conversation when two or more people talk at the same time.
People often complain that you turn up the volume too high on the television or radio.
You have to strain to understand conversation.
You have trouble hearing in a noisy background.
You often find yourself asking people to repeat themselves.
Many people you talk to seem to mumble or speak unclearly.
You misunderstand what others are saying and respond inappropriately.
You have trouble understanding the speech of women and children. (Women and children typically speak in higher frequencies, which are the first frequencies to be affected by NIHL.)
People get annoyed because you misunderstand what they say.
Hearing Aids and NIHL
If NIHL could be corrected the way glasses and contact lenses correct poor eyesight, then encroaching deafness wouldn’t seem as dire. Unfortunately, NIHL is a cumulative disorder, usually taking many years to develop. Over time, sufferers of NIHL find they lose the ability to hear both softer sounds and higher frequencies.
Extended exposure to noise may damage the hair cells in the inner ear. At first, this damage is temporary, particularly if exposure is no more extensive than a single rock concert or a day on a motorboat. Many people have walked out of a concert arena with “filled” ears, making it hard to hear for a few hours. Eventually, full hearing returns.
Over time, however, continuous exposure to excessive noise causes the hair cells to sustain so much damage that the “hair” bundles break off and cannot sense sound, and they may also die. Hearing aids can’t restore something that is broken of or dead. Despite continual improvement in hearing aids, both in their effectiveness and size reduction, and the fact they may improve amplification, wearers cannot regain perfect (or near perfect) hearing. Furthermore, hearing aids in higher noise environments could accelerate NIHL by adding to the daily dose the person receives because of their amplification. Therefore, hearing aids should only be used in quieter areas.
Noise in the Workplace: A Pervasive Hazard
Imagine listening to your kitchen garbage disposer (approximately 80 dB) for eight hours at a time. You may throw your hands over your ears at the mere thought. Unfortunately, for millions of American workers, exposure to dangerous levels of noise (85 dB or above) is a daily fact of life.
Over the last 20 years, government agencies have consistently identified NIHL as one of the top concerns of workers. Some occupational health and safety experts even call noise the most pervasive hazard in the workplace. Yet occupational hearing loss is a particularly insidious hazard because it sneaks up on the worker. Because it doesn’t make the headlines like an industrial accident or sudden on-the-job injury might, noise is a stealth hazard that attracts little attention from the public.
The problem of noise in the workplace isn’t new. For example, the problem of “blacksmith’s deafness,” from the continual clanging of metal on metal, dates back hundreds of years. But since World War II—when noise-induced hearing loss began attracting serious attention as soldiers returned from battle with hearing problems—there’s little question workplaces have gotten louder.
From airports to construction sites, street repairs to landscaping, even large restaurants—workers face a continual barrage of noise. Belt sanders (93 dB), bulldozers (105 dB), chain saws (110 dB), and pneumatic drills (119 dB) are just some of the offenders. Even people in seemingly glamorous jobs suffer from noise exposure. Probably the most famous case of NIHL is rock musician Pete Townshend, lead guitarist of the band The Who, who claims to be mostly deaf from exposure to loud music at the band’s concerts and rehearsals.
Why Is Hearing on the Job So Important?
For some people, the idea of being able to shut out a difficult boss or cranky customer must seem appealing, but that is neither realistic nor safe. In fact, when it comes to hearing problems on the job, that is a downright unsound idea.
Hearing is vital to many aspects of safety and performance. Other than communicating with one another, workers must be able to hear announcements and pages over a public address system, as well as fire and other evacuation alarms or vehicle back-up signals. Equipment operators rely on subtle changes in sound to gauge whether their equipment is running correctly. Many equipment operators cite the need to “hear” their machines as a reason for not wearing hearing protection; they actually will be able to hear the machines better with hearing protection than without, but will need time (a week or two) to adjust to the differences in their perception. The lower frequency noise of a grinding machine transmit well through hearing protection, much like the lower frequency of drums from music transmits well through a closed car.
Good hearing helps workers avoid accidents and reduces the likelihood of serious injury. Studies show that workers in high-noise environments typically lose more time from accidents and are less productive than those exposed to lower noise levels. In addition, evidence shows that continuous high levels of noise cause worker stress, fatigue, and post-work irritability. In some studies, noise has even been linked to increased blood pressure.
Although workers in any field can be exposed to high levels of noise, certain industries have a greater risk. According to the National Institute for Occupational Safety and Health (NIOSH), industries such as mining, agriculture, construction, manufacturing, utilities, transportation and the military run the highest risk of NIHL. Although it is well known that rock musicians create massive waves of sound, even classical musicians—particularly those in orchestras—also experience high decibel levels. (Think row upon row of violins, trumpets, and percussion.)
Hearing Conservation Programs—Protecting Workers from the Start
The best way to prevent hearing loss is by avoiding excessive noise exposure in the first place. Fortunately, although NIHL is still common, it is completely preventable if companies establish effective hearing conservation programs. The Occupational Safety and Health Administration (OSHA) promotes federal noise- related guidelines that workplaces must follow, although some states also regulate workplace noise.
The first line of defense against occupational noise is to diminish loud sounds at their source, wherever possible. Such methods are called engineering controls and involve measures such as installing “silencers” (mufflers and baffles, for example) on equipment. Silencers work by absorbing sound—the muffler on your car is a good example. Acoustic barriers (such as specially constructed walls) can dampen sound from nearby machinery and are another excellent way to guard hearing. There is a national “Buy Quiet” movement to try to get companies and the military to buy quieter machinery, and to specify the sound output acceptable in the procurement order process. Here is what the U.S. Navy has to say about their “Buy Quiet” initiatives:
The "Buy Quiet" approach requires designers and engineers to obtain noise emission data before purchasing to choose the quietest available and affordable equipment. Noise emission values obtained from various suppliers can be compared with each other, and can be used for prediction of the noise levels in the area where equipment is to be placed.
Even though quieter equipment generally can be more expensive to purchase, the equipment is usually better built and has high efficiency. It also can require a simpler noise control installation. These features help to reduce the operating and maintenance costs of the equipment, reducing its total life cycle cost.
The Centers for Disease Control and Prevention (CDC) has a Power Tool Database that lists the noise output of some equipment. This can be used to help with a “Buy Quiet” program.
If the equipment cannot incorporate a silencer or acoustic barrier, or other engineering controls prove impractical, or if the worker cannot be moved away from the noise source entirely, the last line of defense to dampen noise is by blocking the noise with hearing protection devices (HPDs), such as earplugs or earmuffs. The number, variety, and effectiveness of HPDs have improved steadily since World War II. In general, HPDs do not eliminate all sound—which would be both impractical and potentially dangerous—but, if properly used, they reduce noise to safer levels.
Unfortunately, HPDs have one big drawback: no matter how effective the device, it only works if the wearer fits it correctly and uses it when necessary. This is true of hearing conservation programs in general. They rely on the cooperation and motivation of workers and management alike to make them effective. If their only purpose is to avoid an OSHA citation, achieving the goal of protecting workers’ precious hearing may be compromised. To overcome some of these problems, several HPD manufacturers provide methods of “fit testing” hearing protection devices. These are becoming valuable for ensuring that HPDs work well on the individual.
Both employers and workers must be educated about the importance of good hearing and avoiding NIHL. While this may seem self-evident, many people hold common misconceptions about hearing loss. Young people often view it as an older person’s concern, while others mistakenly believe hearing aids will fully restore any loss. Management, too, must commit to the program, whether for humanitarian or business reasons. Every successful work-related hearing conservation program requires buy-in from every level of the workforce.
Noise in the Community: No Quiet Place?
Anyone who has heard a leaf blower while trying to sleep in on Saturday morning is well aware noise isn’t a problem only in the workplace. Like on-the-job noise, people have complained of the increasing din in their communities for more than 100 years. As society grows more mechanized, the sounds get louder.
For years, much of the focus was on city noise: ventilation systems, commuter trains, buses. Unfortunately, noise now seems all-pervasive. Even suburbanites and rural dwellers must endure jets flying overhead, heavy traffic, or nearby industrial plants.
In the community, noise levels receive greater attention at night, particularly if they disturb sleep. Also, noise tolerance tends to increase or decrease based on perception. A homeowner in the country usually expects quieter nights (and days, for that matter). But while a city dweller may expect more environmental noise, everyone has the right to retain his or her hearing.
Not all environmental noise emanates from the workplace. In fact, recreation can create a pretty big racket. Some of the loudest sources include: motorcycles (95-110 dB); sporting events (105 dB); fitness clubs (105 dB); stereo boom boxes (100 dB); snowmobiles (100 dB); dance clubs (110 dB); live popular music concerts (120 dB); and firecrackers (150 dB).
The difference between recreational noise and industrial or commercial noise, however, is that individuals have more control over their own behavior. However, adding sound to drown out sound only results in more sound, so don't fight fire with fire when dealing with noise problems in your neighborhood. Blocking road noise with pumped-up music on your headphones could cause more damage than the original problem.
Community Noise Regulations? A Mixed Bag
There is currently no single national community noise statute. The Noise Control Act of 1972, passed by Congress, places responsibility for regulating community noise in the hands of the states and cities. At that time, the Environmental Protection Agency established the Office of Noise Abatement and Control (ONAC). Although ONAC did not have enforcement capability, it provided extensive information about noise to the public and provided advice to states and cities. Unfortunately, ONAC lost most of its funding several years ago, and efforts to restore it to its former strength so far have been unsuccessful.
This grab bag of noise legislation has resulted in different regions of the country having different laws—or no noise laws at all. These variances are particularly challenging to companies with multiple locations, not to mention to the officials who must judge these companies’ compliance with regulations. At this time, only about 13 states have any form of noise regulations, but enforcement is often spotty.
In the three decades since the Noise Control Act of 1972, however, increasing media awareness about noise—and the increasing noise itself—has resulted in the creation of numerous community-based anti- noise groups. These groups, whether acting alone or representing an alliance of grassroots organizations with state and national support, have proven effective. In California alone, more than 40 communities have successfully banned or severely restricted the use of gas-powered leaf blowers; more than 300 cities and towns across the country have done the same. Nonprofit organizations such as the Noise Pollution Clearinghouse provide assistance to communities seeking to limit the noise in their neighborhoods.
What You Can Do on a Personal Level
There are several steps you can take to reduce noise in your community and protect your hearing—and your peace of mind.
Turn down the volume
Today, many people play their television sets and personal stereos unnecessarily loud. Consider lowering the volume. When purchasing headphones, look for ones with volume limiters that keep the sound at safe levels. This is especially important when buying them for children and teenagers, who often like to test the limits of their gadgets.
Earplugs are inexpensive and come in a variety of types, sizes and colors. And don’t be afraid to speak up for better hearing. If your fitness class instructor has to shout to be heard, for instance, then the music is too loud. Politely ask to turn it down.
Reduce your exposure
Some situations are inherently noisy, but you can decrease the risk of NIHL in several ways. Try to avoid going to loud bars, restaurants or clubs for hours at a time. When riding motorcycles, personal watercraft and other loud vehicles, limit the time you spend on them, or wear ear protection. And it’s never a good idea to play with fireworks for a variety of reasons, including the risk of NIHL.
Remember your neighbors
Noise from your personal recreation affects not only you but everyone around you. Be a good neighbor and lower the volume. This is true whether at home, the beach, a campsite, or a shopping mall—anywhere your loud noises could interfere with others’ peace.
What You Can Do on a Community Level
So what do you do when a local disco spills loud music into the street, or your neighbor’s dog barks all night, or those darned leaf blowers annoy your ears and disturb your peace?
If you have a noise complaint, first try to resolve it in a non-confrontational manner. This is particularly effective in an over-the-fence dispute, as opposed to a commercial noise offender. If the dog next door barks all night, talk to its owner before calling the police. Most of these disturbances end quickly once the noisemaker realizes that his or her actions disturb others.
If that doesn’t end the dispute, however, become familiar with your state and local noise control laws. Once armed with this knowledge, you may want to consider professional mediation before contacting regulatory authorities, A mediator can intervene between you and the noisemaker without involving legal sanctions. For best results, have a trained professional, like an industrial hygienist, measure the noise properly to document the exposure.
If negotiations involving a mediator don’t work and the problem remains unresolved, you will have to turn to authorities, which may include the police, state or local environmental protection offices or your city council.
If you still don’t arrive at a satisfactory conclusion to the problem, it may be time to form your own anti-noise group. Talk with your neighbors and colleagues. Chances are that if a community-wide noise source bothers you (such as leaf blowers), it bothers them too.
Noise pollution isn’t something that you should just accept as a fact of modern life. Noise-induced hearing loss is preventable if we take responsibility for the health of our ears and if we work with others to lessen the impact that noise has in the workplace, the community and in our homes.
In addition to AIHA, the following organizations offer information on noise and noise-induced hearing loss.
Noise Pollution Clearinghouse. (888) 200-8222. A not-for-profit organization with an extensive database of information on noise in the community and the workplace.
The League for the Hard of Hearing. (888) NOISE-88 [888-664-7388]; TTY: (917) 305-7999. Founded in New York in 1910, the league’s noise center promotes hearing conservation and noise awareness.