Posted by Liz Ernst on Fri, Jun 24, 2011 @ 09:57 AM
For NASCAR drivers, crew members, staff and fans, the noise and reverberation that are Nascar's trademark may also be contributing to the most serious health issues fed by extended exposure to the painfully loud roar of four dozen revving engines, blasting around the half-mile oval racetrack at Bristol Motor Speedway. And these are just practice runs.
For many fans, the noise is is huge part of the excitement of Nascar. To the fans, who must shout to communicate, noise delivers the energy that keeps bringing them back for more.
The noise also makes it more hazardous not only for everyone else who spends time at a racetrack during a Nascar event. That is the finding from two studies by the National Institute for Occupational Safety and Health, or NIOSH, which reports that sound levels at tracks reach dangerously high decibel levels.
The first study by NIOSH, the government agency that conducts research on health and safety issues, was published by The Journal of Occupational and Environmental Hygiene in August 2005. It focused on tests conducted at Bristol Motor Speedway.
A co-author of the studies, Dr. Luann E. Van Campen, said NIOSH viewed Bristol as a worst-case scenario for noise because of the bowl-like stadium track surrounded by stands that rise 21 stories. Chemical and noise exposures were measured at Bristol and at an undisclosed race team shop. The study found chemical exposure to be low but noise exposure high.
“Employees involved in stock car racing are routinely exposed to extreme levels of noise, and auditory damage will ensue eventually,” according to the report’s conclusion. “More immediate concerns include the occupational risks posed by possible noise-induced fatigue, stress and miscommunication.”
Chucri A. Kardous, a NIOSH engineer and a co-author of the studies, said the noise level of 43 cars during a race was equivalent to a jet engine, which is 140 decibels.
“It’s higher than what we call here at NIOSH an allowable limit,” he said.
The second study, a follow-up that includes other tracks, was not available as it was being prepared for publication. But some of the results were presented last fall at a gathering of the Acoustical Society of America.
As in the first study, peak sound levels exceeded 140 decibels during races. To put that in perspective, noise becomes painful at 125 deciels; even short term exposure to decibel levels at 140 can cause permanent hearing damage. This is the loudest recommended exposure to noise with hearing protection. NIOSH typically recommends having protection when levels exceed 85. An abstract of the second study also noted how quickly the noise reached that level: “in less than a minute for one driver during practice, within 2 minutes for pit crew and infield staff, and 7 to 10 minutes for spectators during the race.”
That exposure could last for three or four hours, the duration of a race.
Kardous said he could not find any other studies of noise at racetracks. The Nascar spokesman Jim Hunter said officials had not focused on the matter since the 1970s, when noise became an issue primarily among people living near racetracks.
But the NIOSH findings are hardly a shock to those who spend time at the track. The seven-time champion Richard Petty has blamed racing for his hearing loss and now wears a hearing aid.
After 32 years of racing everything from go-karts to stock cars, including 14 seasons in Nascar’s premier Cup series, the driver Jeff Burton is a victim, too.
“My hearing’s not great, but there’s a reason for that,” he said as teams arrived for the Sharpie 500 race Saturday night. “When I was younger, I didn’t worry a whole lot about it. But I do now. Maybe too late.”
Many drivers use custom-molded plastic earplugs during races; Burton wears foam plugs. He said he did not know the Noise Reduction Rating for his ear protection. The rating indicates the number of decibels a protection device can block.
Crew members and other Nascar staff members typically wear communication headsets during races. Nascar requires its employees to wear protection. The headsets protect the ears but lose some of their effectiveness when the volume is turned up to allow communication among staff and crew. Fans who use similar headsets to listen in on scanners of driver-crew conversations face the same loss of protection, Kardous said.
There have been no studies conducted to determine the proper Noise Reduction Rating for drivers, crew members and fans at Nascar events. One of several recommendations from the first report included further studies on proper protection levels for earplugs and headsets. Those recommendations have not been followed.
Thais Morata of NIOSH, another co-author of the studies, said it would be up to Nascar, drivers or teams to approach the institute about further research. No studies are planned.
There may be another option. Nascar could use mufflers to reduce the noise during races.
“That’s the primary source of the noise, so obviously, that would be the top recommendation if we could make it,” Kardous said.
But Hunter said that Nascar tried mufflers in the 1960s and that they did not have a significant effect on decibel levels. Besides, it would be a hard sell for fans, who prefer to attend practices and races without any hearing protection.
Excerpted from an article by Viv Bernstein, published 2007, New York Times.
Posted by Liz Ernst on Wed, Jun 08, 2011 @ 09:05 AM
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.
Posted by Liz Ernst on Thu, Jun 02, 2011 @ 08:18 AM
Creating a quiet and private oasis in a front or back yard, one that will cut traffic noise, noise from nearby trains, barking dogs, the noisy generators and heat pumps in neighbors’ yards, and even the noisy neighbors themselves is an excellent investment, not only in your home’s value, but in the quality of your lifestyle.
Traffic noise is actually one of the most difficult soundproofing projects that any soundproofing engineer or acoustical consultant could ever have to tackle. In essence you are trying to soundproof the outdoors, from the outdoors. It is tough to accomplish, but there are methods that can block noise dramatically and give you the private and serene yard you long for.
A fence alone will do nothing to block traffic-generated noise. A fence or barrier made of stone or masonry will increase your chances of blocking the noise but depending on your budget, where you live, and your city’s ordinances, you may be prohibited from constructing this type of fence.
Some city ordinances also limit fence heights to six-feet, eight-feet or 10-feet. Since the “line-of-sight” rule says that if you can see the source of the noise by looking over the fence, you will be able to hear it; although attaching sound blocking fencing material to a six-foot fence will significantly decrease noise, a fence built eight- to 10-feet high with sound barrier fencing material attached will create a seriously quiet oasis in any back yard. Homeowners can enjoy family time, entertaining, and simply sharing a quiet meal outdoors without external noise infringing, and without disturbing their neighbors.
If you are planning to build a wooden fence (dog eared slat type) then all the gaps in the wood fence must be caulked in with a good acoustical caulk. After you have caulked the gaps between the slats, you will need to line the backside or the side facing the traffic, with a high quality outdoor noise blocking fencing material made specifically for this type of application.
Some noise reduction fencing material comes with anodized brass grommets across the top and bottom, allowing it to be easily hung over the existing fence (wood, chain link, or other structure) and secured with heavy duty nylon wire ties. It can be hung on the outside of the fence facing the noise source, or on the inside of the fence, facing the property, and can be removed and reused for special events, or kept in place permanently.
More and more landscape architects, gardeners, and homeowners are utilizing noise abatement fencing to create a private, peaceful backyard retreat. When choosing a noise abatement material to hang on an existing fence, installation should be easy, and care must be taken to install it properly so that no gaps remain between sections of noise reduction fencing material. Overlapping sections eliminates any worry of noise seeping through.
A sound abatement consultant can provide you with professional advice when it comes to choosing the best noise abatement fencing product and its application, according to the height of your fence and the level on noise control you wish to achieve.
When installing any sound barrier fence, curb appeal is an important factor, in addition to the product’s appearance within the yard. Acoustical fencing in itself offers no aesthetic value, but can easily be camouflaged with greenscaping that blocks the view of the fence. When designing a yard for acoustic comfort, there are plenty of options to use foliage as an aesthetic finishing touch.
Additionally, there are high-quality fencing attachments available that actually hang directly over the acoustical fencing, to camouflage an entire fence with scenic landscapes. These attachments can create the illusion that the fence blends in with the existing landscape, or they can create a whole new aesthetic. With hundreds of designs available, and the option to have a custom scene made, these landscape attachments, which are made of UV resistant solar shade material (the same material used in patio umbrellas and outdoor furniture fabrics) are an excellent option for hiding an acoustical fence. They can be hung to face the street, and they can be hung to face the yard, or both.
Your backyard should provide a tranquil and private retreat, where the grounds are shielded from external noise, and your family can have fun and privacy year round. Installing the right acoustical fence is the first step toward achieving that goal.