Just Too Loud
Ted Rueter isn’t joking about possibly moving to New Zealand. And if he does go, it won’t be the rage or the expense of living in the U. S. that drives him away. It will be the leaf blowers. Americans now own more than 90 million of the evil things, he says, each of them the job of lawn clearing much easier—and much, much louder. Rueter, a professor at UCLA who is head of the advocacy group Noise Free America, already fled Los Angeles to get away from the leaf-blower bother, only to move to New Orleans and find the problem just as bad there. "Everywhere has turned into leaf-blower hell, "he says.
It’s not just the blowers that are driving Rueter daft. It’s the boom ears—those high-decibel(分贝) ,low-fre- quency speakers on wheels that cause your windshield to buzz and your eardrums to pulse’ when they pull up next to you at a stoplight. It’s the car alarms too, as well as the barking dogs and the banging garbage trucks and the screaming airplanes and the roaring highways. It’s the explosion of ambient (周围的) noise that seems to be everywbere, costing more and more people not only their sleep and their sanity but increasingly their hearing and health as well.
According to the National Institutes of Health, more than 10 million Americans already suffer some permanent noise-induced hearing loss. They report that some 30 million are exposed to daily noise levels that will ually reduce their ability to hear. One in eight children between the ages of 6 and 19 already have some degree of hearing loss, and s who are going deaf are doing so earlier and earlier. "The greatest increase in noise-re-lated hearing loss occurs for people a5 to years old," says Dr. James Battey, director of the National Institute on Deafness. "This is almost 20 years younger than we would expect."
And it’s not just our ears the noise is hurting. It-takes sounds in excess of 85 db to damage hearing, but noise at less than 75 db may be linked to hypertension, and that at just 65 db leads to stress, heart damage and depression. Think the noise in your environment doesn’t rise to that level Think again. A ringing telephone can reach 80 db; a hair dryer hits 90 db; an ambulance siren can top out at 120 db. "Noise pollution is truly a public health threat, "says Representative Nita Lowey of New York, who has reintroduced a bill in Congress to turn down the volume. "It’s critical," she says, "that we work to diminish the impact noise has on our communities."
The booming of America has many causes. Population growth in city centers, loss of rural land to sub sprawl, and the soaring number and size of cars on the highways all play a role. So too does the entertainment industry, with Walkmans, Pods and surround-sound theaters pouring noise into consumers’ ears. Even sports stadiums, always noisy places, have got louder as earsplitting commercials fill the comparatively quiet interludes that used to prevail during pauses in the action.
Whatever the roots of the problem, the noise is now everywhere—and the workplace may be the worst place of all. At least 20% of US workers do their jobs in environments that could ener their hearing, according to NIOSH. The US government estimates that more than 90% of coal miners suffer hearing impairment by age 50. Even farms are not exceptional: according to the New York Center for Agricultural Medicine and Health, a staggering 75% of farmers now exhibit some hearing impairment, mostly as a result of noisy equipment. "Hearing loss is one of the most common workplace conditions, "says audiologist Ted Madison.
For kids, the racket starts in the cradle. A squeaky toy held close to the ear—which is precisely where babies may put them—can reach 94 db. A toy xylophone(木琴) can ring in at 92 db. And since babies’ ear cs are so small, a sound that gets in them may knock around harder than it docs in an ’s ears and do comparably more damage.
Noise can be controlled to an extent, depending on the source. Some of the biggest sources of ambient noise are highways and roads, but the cause is less honking(使鸣响) horns or gunning engines—though those play a role—than tires hitting pavement, flexible rubber contact with asphalt(沥青) doesn’t seem as if it would produce a lot of noise but in fact it does. As any spot on the tire strikes the highway, it hits with the thunk of a little rubber hammer. Also, the patch of tire that’s in contact with the ground at any instant—the so-called tread block—an squeak like a sneaker on a gym floor. Air pumping through tire grooves makes noise of its own.
The solution, says engineer Bob Bernhard, is to change not the tires but the road suce. "You can make the pavement porous," he says," which affects the air-pumping mechanism. You can also mix a little rubber in with the asphalt, which changes the road’s stiffness. "Porous suces are already being rolled out in parts of Georgia, Florida and Arizona, as well as in Europe.
Road noise that cannot be eliminated can be covered. More and more highways are being framed by high walls, additions that do little for the view but an awful lot for the peace and quiet of the people living nearby. The walls reduce noise by either reflecting or absorbing it. This low-tech though pricey fix—about ＄1 million a mile—educes sound levels only as much as 7 db, but given the exponential way noise propagates, that’s a lot. "A 10-db reduction may work out to a halving of loudness," says Nicholas Miller, head of Harris Miller Miller ＆ Hanson, a noise-consulting firm in Burlington, Mass.
Airport noise is harder to restrain but not impossible. An airport can determine which of its runways require a plane to fly over the least populated area and use those as its default approaches. Miller’s firm recommends that noisy banking on takeoffs and landings occur over water where possible. Other studies suggest that pilots eliminate the stair-step method of descending from flight and instead ease down at a smooth angle to eliminate a lot of noisy throttling.
Local governments have also started to step in. In 2002, New York City launched a campaign called Operation Silent Night to crack down on noise in 24 high-volume neighborhoods. Police officers with noise meters impose fines from ＄45 to ＄25,000—the highest ones going to scofflaw(常违反法规者) businesses like nightclubs. Noise summonses jumped 20% in the first year, the city not only quieter but safer too, since some of the noisiest offenders turned out to have outstanding warrants for more serious offenses.
The European Union has been somewhat more aggressive in combatting noise. Calls for explicit limits on noise were rejected by the European Parliament, but compromise legislation does require all member countries to produce color-coded,3-D noise maps of all major cities, enabling planners to spot the biggest problems at a glance. The maps, which must be completed by 2007, can then be used for computer models to test the noise impact of a new building or street design before construction begins.
In the US, there is still no comparable program. Representative Lowey’s bill, now pending in Congress, would provide ＄20 million a year for noise reduction and reopen the shuttered noise-abatement office. Some appliances are now designed for reduced noise, and a uniform-labeling program could enable consumers to compare decibel levels the same way they compare energy efficiency in a toaster or dishwasher.
Such micromanagement of noise may never be entirely possible, but it may be the best of an imperfect array of options. The alternative—walling ourselves off behind a thickening barrier of earplugs, triple-glazed windows and white-noise machines—may keep down the noise, but it will also deafen us to much of the world, not just the parts we don’t want to hear. Sports stadiums now becomes a source of noise pollution because of ______.