MY most recent furlough from city life changed the way I look at noise. I used to think of it as an irritant. Now I think of it as a pollutant. Here's the difference: the first is annoying, the second is destructive. Three trivial incidents, that's all it took. Hours from the nearest paved road and invisible to neighbours, the cabin was a perfect oasis after an especially gruelling stint of urban warfare. When I arrived, late at night, I had only one thing on my mind: sleep. I turned out the lights and waited for sweet Morpheus. But the Roman god of dreams never came. I couldn't figure it out. I hadn't drunk too much coffee, I wasn't anxious, the music-loving insomniac in apartment 5D was 400 kilometres away. What could the trouble be? Then it hit me. It was the very absence ofcity sounds - distant sirens, cackling radiators, muffled voices through the wall - that was keeping me awake. I had grown so accustomed to background noise that I couldn't sleep without it. The problem is, I can't sleep with it either - at least not well. I'm not alone. Millions of my fellow American urban dwellers, according to scientific studies, also sleep without resting, listening as they toss and turn to the unrelenting cacophony of the city: refuse trucks, car alarms, night construction, squealing subway wheels, car stereos loud enough to rattle windows, air traffic, ambulances and mental misfits howling at their misfortune, or perhaps just at the moon. That night, my fear-of-silence syndrome only lasted a few hours, after which I slept like a hibernating bear. The next morning, strolling through a grove of pine, I heard and then spied a woodpecker working over the trunk of a half-dead tree. His modus operandi was obvious: attack the wood with a staccato burst, cock an ear to listen for bugs beneath the surface, and then go in for the kill. I watched him repeat this pattern a few times, but then he stopped. That's when I noticed the sound of jet engines. We were, the woodpecker and I, on a commuter flight corridor. I barely noticed, but the bird sure did. Each time a plane flew overhead he couldn't hear the bugs, so he had to wait. With jets passing by every 20 or 30 minutes, I figured the woodpecker was losing about 15 per cent of his hunting time. The final incident, the one that crystallised my new thinking about noise, came on the last day of my week-long retreat. I had, by that time, unwound. Even my toe nails were relaxed, which is why it came as such a shock out there in the middle of 10,000hectares of wilderness: a car alarm. An undulating, nerve-destroying, peace-shattering car alarm. I put on my boots and removed a long-handled axe from the tool shed. But no sooner had I started out in the direction of the noise then it stopped. New York City has more than a handful of car-alarm vigilantes whose weapon of choice is spray paint. (I'm not one of them, but only for lack of courage). Defacing a car doesn't stop the noise, but it gives the feeling, as one vigilante put it, that ''justice has been served''. Among the growing legion of urban dwellers upset by noise pollution, however, the vast majority are seeking to alleviate their ear drums through legal means. New York's city council recently debated a proposal to stiffen the penalties for car alarms thatbleat for longer than three minutes (the current limit is 10) to require cars with audio alarms to display the owner's phone number, and to give the police the authority to tow, rather than just ticket, offending vehicles. But some of these measures are unenforceable, others an infringement of privacy, so the ordinance was never passed. Besides, in a city grappling with budget constraints and one of the worst violent crime rates in the Western world, fighting decibels isn't a top priority. Oddly enough, if the experts are right, it should be. Because noise pollution is more than portable phones in restaurants or beepers in church. It is a real threat to health and mental well being. Doctors and scientists agree that sustained noise levelsabove 80-90 decibels cause or contribute to loss of hearing, reduced learning ability, extreme stress, aggressiveness, ulcers and high blood-pressure. About 15 per cent of the American population live and work in noise-polluted environments. The hazards of sustained exposure to high levels of noise have been known for a long time. Indeed, in the decade following the enactment of the 1972 Noise Control Act by Congress, nearly 1,000 municipal anti-noise programmes sprung up around the country. In 1982, however, Ronald Reagan gutted the federal government's noise abatement powers. Today, as a consequence, less than 100 of the local programmes remain. But the forces for silence are gathering momentum once again, not just in the cities but in the suburbs too, where everything from leaf-blowers to airports are more and more subject to noise-reduction regulations. A new, environmentally sensitive administration in Washington is likely to give an added boost. It is not, perhaps, obvious that noise is pollution in the same way as toxic waste, smog or untreated sewage. You can't touch it, taste it, smell it, or see it. But noise just as surely wrecks the quality of our lives as all these other pollutants. And no matter how hard you try, you can't - and shouldn't - get used to it.