Sound, or more specifically, noise, is an invisible pollutant that can harm our ears, our hearing, and our health.
Think back to the last time you went to a rock concert or a particularly high volume club; when you left, did you pay much attention to the peculiar ringing in your ears as you headed back to your car, maybe even after you returned home? The sound around you were muffled for a short while, replaced with a buzzing inside your head, almost as if your ears were screaming.
In a way, they were.
IISo, what do we need to know about protecting out ears from IIloud noise, and what do we do when the ringing never stops?
IINoise pollution is encroaching on the everyday lives of all of IIus, and the more we understand about how noise effects our ears, our hearing, and our health and well being, the more IIlikely we are to take action to make changes.
Hair cells within the inner ear.
Noise levels louder than a shouting match can damage the hair cells of the inner ear. These delicate hair cells Hair cells within the inner ear contain act as the "gatekeepers of our hearing. When sound waves hit them, they convert those vibrations into electrical currents that the auditory nerves carry to the brain. Without hair cells, there is nothing for the sound to bounce off - compare it to trying to make your voice echo in the desert.
Hair cells reside in the inner ear inside the shell-shaped cochlea. Bundles of hair-like extensions, called stereocilia, rest on top of them. When sound waves travel through the ears and reach the hair cells, the vibrations deflect off the stereocilia, causing them to move according to the force and pitch of the vibration. For instance a soft piano sonata would produce gentle movement in the stereocilia, while heavy metal would generate faster, sharper motion. This motion triggers an electrochemical current that sends the information from the sound waves through the auditory nerves to the brain.
When you hear exceptionally loud noises, your stereocilia actually become damaged and mistakenly keep sending sound information to the auditory nerve cells. After spending time at a rock concert, a loud club, an active race track, an air show, an industrial plant with unmitigated chillers or machinery, or even in heavy traffic, the ringing happens because the tips of some of your stereocilia actually have broken off. You hear the false currents in the ringing in your head, called tinnitus. However, since you can grow these small tips back in about 24 hours, the ringing improves and goes away over time.
There are two ways hearing can be damaged by loud noises, according to Manfred Auer of Berkeley Lab's Life Sciences Division. Noise can stress the stereocilia bundle so much that the tip links break, which Auer refers to as the rock-concert effect, where hearing loss is temporary and the stereocilia tips grow back.
However, loud noises can also shear off whole bundles of stereocilia. In mammals these can't regenerate - the loss is permanent.
Repeated exposure to loud noises can kill the hair cells entirely. So what? We have 16,000 of them in each cochlea, but that number pales in comparison to the eye's 100 million photoreceptors, which do to light what hair cells do to sound. In addition, once those hair cells die, we cannot growth them back. This is why protecting your ears is essential.
How loud is too loud? Sound is measured in units called decibels. Decibels measure the power of sound, rather than the amount. Safe sound levels are considered below 85 decibels. Here's another rule of thumb: If you have to shout to hear someone an arm's length away, the sound is probably above that safety threshold.
Repeatedly crossing that 85-decibel threshold can have unpleasant consequences. While the ringing in your ears from a loud noise is usually brief, for more than 12 million Americans, it never stops, according to the American Tinnitus Association. Chronic tinnitus can be a symptom of infections, high blood pressure, even compacted earwax, but it is commonly associated with noise-related hearing loss.
There are a few simple ways to safeguard your hearing. First, be aware of the noise levels around you. If you know you're going to be in a loud environment, wear earplugs to protect your ears. Also, notice how close you are to the source of loud noises and how long you're exposed to them. And pay attention to the ringing in your ears. Our bodies are sometimes more fragile than we think.
Many organizations and publications that promote green living, green construction, green manufacturing, and green energy focus on unhealthy pollutants that take the form of toxic or non-biodegradable waste.
Isn’t it time to include noise in the roll call of un-green, unhealthy pollutants?
Green living has taught us that every time a SUV is driven solo (no passengers), it’s adding more than 1.5 pounds per mile of carbon dioxide or other greenhouse gases to the environment. In the spirit of living green, many of us have changed our driving habits for the sake of the environment. We drive smaller cars, we carpool, and we take short trips on foot or by bike instead.
We buy reusable containers for carrying around water, and when we do buy bottled, we recycle the empties. We feed our families more organically-grown foods these days, and clean our homes with non-toxic cleansers because living green is healthier.
So when you consider the toll that noise pollution is taking on our health every day, you would think that addressing noisy matters would be number one on the list of “green living” priorities, or at least in the top five.
Noise pollution is a modern plague; it affects our hearing, our sleep patterns, our performance levels, and even the way food tastes. It has been documented to increase risks of heart disease and stroke. Noise pollution – from the neighbor’s constantly barking dog, to the unwelcome sounds of air and ground traffic, construction, manufacturing plants, lawn equipment and the hundreds of sources of ambient sounds that infiltrate our space daily – is not a component of green living.
Exposure to sound levels in excess of 85 decibels for more than eight hours is potentially unhealthy. Eighty-five decibels is roughly equivalent to the noise of heavy truck traffic on a busy road.
Above 85 decibels, hearing damage is related to sound pressure (measured in decibels) and to time of exposure. The major cause of hearing loss is occupational exposure to noise, although other sources (particularly recreational noise) are also culprits. Studies suggest that children seem to be more vulnerable than adults to noise induced hearing impairment. Children in noisy environments are also found to have more difficulty reading and learning, and experience a diminished quality of life.
Children, the elderly, and those with underlying depression may be particularly vulnerable to noise pollution because they may lack adequate coping mechanisms.
Noise pollution impairs task performance at work and in school, increases errors, and decreases motivation. Focusing, problem solving, and memory are most strongly affected by noise.
Although noise pollution is not believed to be a cause of mental illness, it is assumed to accelerate and intensify the development of latent mental disorders, anxiety, stress, nervousness, nausea, headache, emotional instability, argumentativeness, sexual impotence, changes in mood, increase in social conflicts, neurosis and psychosis. Population studies have suggested associations between noise and well-being, the use of psychoactive drugs and sleeping pills, and increased mental-hospital admission rates.
Noise levels above 80 decibels are associated with both an increase in aggressive behavior and a decrease in behavior helpful to others. News agencies regularly report violent behavior arising out of disputes over noise, often ending in injury or death. The effects of noise may help explain some of the dehumanization seen in the modern, congested, and noisy urban environment.
Noise pollution effects the environment very differently than regular fossil fuel pollution, but it can still have very negative effects. For this reason, many states and counties have developed noise control laws that designate exactly how much noise a vehicle can legally emit, or how loud a band can play in an outdoor restaurant. The problem with noise control laws, however, is they can be very difficult to enforce.
Green living is the healthy result of decades spent educating people on the ill effects of pollutants and ways to undo their damage. It’s time to include noise in the green education process that has produced citizens who recycle, compost, preserve water and energy, and look at the items bought and used every day differently than their parents and grandparents did.
It’s time to up the bar; involve citizens in managing noise wherever possible, and demand that businesses and other noise offenders do the same.
Noisy generators and HVAC units, pool pumps, car stereos played at heart-pounding volume and noise generated from a cranked home stereo all contribute to noise pollution. Even the drive to work and the eight-or-more hours spent there expose us to onslaughts of noise – construction, traffic, sirens and horns blaring, manufacturing plants, machinery and more – that take a toll on our health and wellbeing.
Even after years of living with noise in our daily lives, when we think we have become accustomed to it, our bodies are singing a different tune in the form of gradual hearing loss, cardiovascular disease, stress, sleep deprivation and other symptoms.
For one week, everyone shoud take note of the various noise sources that have become a part of their everyday lives. This might be a good start to recognizing those sounds that are harmful, and finding solutions to managing or eliminating the most damaging culprits.
We can even adapt some existing green slogans to eradicating noise:
Green revolution, the best solution to noise pollution.
I hear the Eco.
Be Quiet! Go Green!
Every year, approximately 30 million people in the United States are occupationally exposed to hazardous noise. Noise-related hearing loss has been listed as one of the most prevalent occupational health concerns in the United States for more than 25 years. Thousands of workers every year suffer from preventable hearing loss due to high workplace noise levels. Since 2004, the Bureau of Labor Statistics has reported that nearly 125,000 workers have suffered significant, permanent hearing loss. In 2009 alone, BLS reported more than 21,000 hearing loss cases.
Exposure to high levels of noise can cause permanent hearing loss. Neither surgery nor a hearing aid can help correct this type of hearing loss. Short term exposure to loud noise can also cause a temporary change in hearing (your ears may feel stuffed up) or a ringing in your ears (tinnitus). These short-term problems may go away within a few minutes or hours after leaving the noisy area. However, repeated exposures to loud noise can lead to permanent tinnitus and/or hearing loss.
When no sound barrier is in place, loud noise can also create physical and psychological stress, reduce productivity, interfere with communication and concentration, and contribute to workplace accidents and injuries by making it difficult to hear warning signals. Noise-induced hearing loss limits your ability to hear high frequency sounds, understand speech, and seriously impairs your ability to communicate. The effects of hearing loss can be profound, as hearing loss can interfere with your ability to enjoy socializing with friends, playing with your children or grandchildren, or participating in other social activities you enjoy, and can lead to psychological and social isolation.
When sound waves enter the outer ear, the vibrations impact the ear drum and are transmitted to the middle and inner ear. In the middle ear three small bones called the malleus (or hammer), the incus (or anvil), and the stapes (or stirrup) amplify and transmit the vibrations generated by the sound to the inner ear. The inner ear contains a snail-like structure called the cochlea which is filled with fluid and lined with cells with very fine hairs. These microscopic hairs move with the vibrations and convert the sound waves into nerve impulses–the result is the sound we hear.
Exposure to loud noise with no noise barrier in place can destroy these hair cells and cause hearing loss!
What are the warning signs that your workplace may be too noisy?
Noise may be a problem in your workplace if:
- You hear ringing or humming in your ears when you leave work.
- You have to shout to be heard by a coworker an arm's length away.
- You experience temporary hearing loss when leaving work.
How loud is too loud?
Noise is measured in units of sound pressure levels called decibels using A-weighted sound levels (dBA). The A-weighted sound levels closely match the perception of loudness by the human ear. Decibels are measured on a logarithmic scale which means that a small change in the number of decibels results in a huge change in the amount of noise and the potential damage to a person’s hearing.
OSHA sets legal limits on noise exposure in the workplace. These limits are based on a worker’s time weighted average over an eight hour day. With noise, OSHA’s permissible exposure limit (PEL) is 90 decibels for all workers for an eight hour day. The OSHA standard uses a five decibels exchange rate. This means that when the noise level is increased by five decibels, the amount of time a person can be exposed to a certain noise level to receive the same dose is cut in half.
The National Institute for Occupational Safety and Health (NIOSH) has recommended that all worker exposures to noise should be controlled below a level equivalent to 85 decibels for eight hours to minimize occupational noise induced hearing loss. NIOSH has found that significant noise-induced hearing loss occurs at the exposure levels equivalent to the OSHA PEL based on updated information obtained from literature reviews. NIOSH also recommends a three decibel exchange rate so that every increase by three decibels doubles the amount of the noise and halves the recommended amount of exposure time.
Here’s an example: OSHA allows eight hours of exposure to 90 decibels, but only two hours of exposure to 100 decibel sound levels. NIOSH would recommend limiting the eight hour exposure to less than 85 dBA. At 100 decibels, NIOSH recommends less than 15 minutes of exposure per day.
In 1981, OSHA implemented new requirements to protect all workers in general industry (e.g. the manufacturing and the service sectors) for employers to implement a Hearing Conservation Program where workers are exposed to a time weighted average noise level of 85 decibels or higher over an eight hour work shift.
Hearing Conservation Programs require employers to measure noise levels, provide free annual hearing exams and free hearing protection, provide training, and conduct evaluations of the adequacy of noise deadening materials in use unless changes to tools, equipment and schedules are made so that they are less noisy and worker exposure to noise is less than the 85 decibels.
Rock legend Pete Townshend of "The Who" has severe hearing damage resulting partly from the band's live gigs, but mainly from the deafening volume in which he used to listen to playbacks over the studio "cans." Completely deaf in one ear, Townshend's hearing damage manifested itself as tinnitus, a condition Townshend calls painful and frustrating.
Hearing loss due to environmental noise is a serious health hazard today, and it is on the rise. Exposure to loud noise for extended periods of time can lead to irreversible hearing loss and other health problems.
Of course there is no one “cure” for noise pollution, but there are preventative measures that can be taken.
Noise induced hearing loss can be generated from industrial noise as well as exposure to any amplified sounds, such as at concerts and nightclubs. Usually, hearing loss experienced from attending an extremely loud event is only temporary and will correct itself in time. However, musicians who entertain regularly in these environments often suffer from moderate to severe hearing loss over the course of their careers. Individuals who listen to music at extremely high volumes routinely are also vulnerable to permanent hearing loss.
Industrial sectors like airline, highway and light rail train systems, mining operations, construction, manufacturing and engineering industries contribute to the most serious levels of industrial noise pollution. In fact, according to OSHA officials, every year, approximately 30 million people in the United States are occupationally exposed to hazardous noise.
Fortunately, the incidence of noise-induced hearing loss can be reduced or eliminated through the successful application of acoustical controls and hearing conservation programs. Employers today must invest in hearing protection measures that correspond to the type of noise and decibel levels to which their employees are subjected.
Generally, there are three levels of noise hazards: Impact noise (as in an explosion or gunshots); Intermittent noise (such as noise generated from heavy vehicle traffic), and continuous noise (machinery that runs constantly, such as generators, industrial pumps, lawn equipment, jackhammers, conveyors, residential heat pumps, etc.).
Businesses with noise issues serious enough to effect employees, visitors, neighbors or pedestrians look for noise reduction solutions that are most adaptable to their particular noise source and are capable of dramatically reducing noise and the health risks that go with it. Businesses with machinery so loud that ordinary conversation is impossible risk additional hazards when employees and visitors cannot communicate adequately.
In some industries such as mining and construction, specially designed ear protectors, or ear muffs offer protection from hearing loss in extreme noise surroundings, and in some instances enable communication by utilizing Bluetooth technology. In other settings, such as airport terminals, hospitals, jails and prisons, restaurants and others that experience high decibel ambient noise levels, sound barriers and sound reduction materials offer more practical solutions to combatting the health risks of noise pollution.
People need to become proactive about protecting their hearing throughout their lifetime. Today, Townshend promotes taking protective measures, including wearing earplugs, to reduce loud music to a level that does not damage the ear.
But it's not loud music alone that is damaging American's hearing. Environmental noise pollution is becoming a plague; individuals need to become proactive when it comes to protecting themselves from all types of damaging noise whenever possible.
Loud noise can have serious consequences to an individual’s health and well being. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, stress-releated illnesses, premature ejaculation, sleep disturbance, decreased sexual performance and even death. Some experts suggest that changes in the immune system and birth defects have been attributed to noise exposure, although evidence is limited. Although some hearing loss may occur naturally with age, in many developed nations the cumulative impact of noise is sufficient to impair the hearing of a large portion of the population over the course of a lifetime. Exposure to loud noise has also been known to induce tinnitus, hypertension, vasoconstriction and other cardiovascular impacts. Beyond these effects, elevated noise levels can create stress, increase workplace accident rates, and stimulate aggression and other anti-social behaviors. The most significant culprits are vehicle and aircraft noise, prolonged exposure to loud music, and industrial noise.
The social costs of traffic noise in European countries and the U.S. is in the billions of dollars per year, with traffic noise alone is harming the health of one in every three people in some high-traffic communities. One in five individuals is regularly exposed to sound levels at night that could significantly damage health.
The location of site and noise generators near sites which are noisy include major roads, railroads, industrial plants, etc. Traffic maps and land use maps from highway departments, planning agencies, railroads, and airport authorities may document such noise generators.
Noise is also a detriment to animal habitats and ecosystems.
Acoustiblok’s all weather sound panels and other noise abatement products are helping industries and individuals combat noise-related problems every day. Acoustiblok’s sound absorption capability is more effective than a 12-inch poured concrete barrier.
The Facts about Noise “Pollution”
According to the Noise Pollution Clearinghouse, “Noise is among the most pervasive pollutants today. The problem with noise is not only that it is unwanted, but also that it negatively affects human health and well-being. Problems related to noise include hearing loss, stress, high blood pressure, sleep loss, distraction and lost productivity, and a general reduction in the quality of life.”
In business, excessive noise can cause irreversible hearing loss, increased worker compensation claims, and higher insurance costs.
Noise problems are hardly confined to industrial areas. Whatever space, there are three essential approaches to controlling or eliminating noise:
- Contain the noise at the source by using mufflers, engineering controls, etc.
- Identify, isolate and treat the many paths noise will take with barriers, absorbers and dampers.
- Cancel the noise by reducing sound at the listener with headphones, earplugs, etc.
Contact Acoustiblok for more information about noise pollution solutions.