This is an archived article that was published on sltrib.com in 2007, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

If you've been to a national park lately, you've probably encountered "sound litter."

Maybe a boom box blared as you watched the stars at Arches' Devil's Garden Campground. Or the chuck-chuck-chuck of neighboring RV generators kept you up at Capitol Reef's Fruita Campground. Or the distant drone of a commercial jet drowned the bird-mating song you overheard in Zion's backcountry.

Buzzing watercraft, screaming motorcycles, sputtering four-wheelers, cranking stereos, chugging generators, jingling cell phones and, of course, helicopters and airplanes roaring overhead - people bring them from their homes in cities and suburbs to help them enjoy the park experience.

It's time, some say, for an anti-litter campaign to clean up the din.

No escape

"Noise is to the soundscape as litter is to the landscape," says Les Bloomberg, executive director of the Noise Pollution Clearinghouse. "For 100 years, we have been filling the landscape with waste, primarily from combustion engines, and now there is no place to escape it."

"The parks should be our last refuge, the places we can go to avoid noise."

The American Acoustical Society recently met in Salt Lake City, where they talked about noise in national parks. And what they heard is not good.

The Grand Canyon is known for "extraordinary silence," said Dickson Hingson of the Sierra Club. An acoustical study released earlier this year describes it as one of the quietest places on Earth, with only the sound on a glassy sea and below unbroken ice being quieter.

That's if you don't count the man-made noise, especially from tourist flights over the canyon and, higher in the skies, commercial jets that fly over on routes between New York and L.A. Noise "now impacts almost every acre," he said.

Grand Canyon visitors can expect to hear aircraft every two minutes, from 8 a.m to 6 p.m. from spring to fall, about 132,000 overflights a year. In about 90 percent of the park, tour planes and helicopters can be heard 100 percent of the time, said Hingson.

The only place you can't hear them, he said, is deep in the canyon on the Colorado River, in the rapids.

Noise researcher Skip Ambrose said the clamor doesn't stop at the Grand Canyon. It continues throughout Utah's five national parks - Arches, Canyonlands, Zion, Bryce Canyon and Capitol Reef.

"There's times when you can't hear the natural sounds," said Ambrose, a biologist who measured noise for the Park Service from Yellowstone to the Grand Canyon and everywhere in between before retiring in the past year.

He can't name a single spot in Utah's national parks free of sound litter. He hasn't measured one. And, given the East-to-West overflights of commercial jets, he doubts there are any, even with the many remote places within Utah's boundaries.

Soundscape

The effort to understand noise in the parks springs from the Park Service's mandate to preserve the natural resources and ensure the visitor experience in the national parks, as expressed in the 1916 Organic Act. In effect, it made the natural soundscape a natural resource.

Assessing park noise has been difficult.

Even the definition of noise is controversial, since the idea that there is "unwanted sound" doesn't apply when park visitors are enjoying the clatter they bring from home, the generators to cool RVs and the boom box music they play at their picnic tables.

In addition, it's been tough to separate man-made noise from natural sounds and to put a fair value on all those sounds.

For instance, it's one thing to measure a visitor's dashed delight when a helicopter drowns out the ruckus raised by dueling pinyon jays. It's another to tally the cost of man-made noise to the peregrine falcons looking for their mates, the hungry cougar stalking a mouse or the wary mouse listening for that cougar's footfall.

"The more we cover up the natural sounds," said Ambrose, "the more it affects them."

Fights have erupted over tourist flights at the Grand Canyon, Bryce and Canyonlands, commercial flights over Zion and snowmobiles in Yellowstone.

And the public review process and the courts have helped improve the sound landscape.

But all of it has fallen short of restoring the natural quiet the Park Service and park advocates have sought.

Some of the problem is that noise restrictions aren't enforced, noted speakers at acoustical society meetings.

And Ambrose blamed at least some of the problem on the park itself. Park managers could, for instance, use less noisy tools than aircraft for surveying wildlife. Parks could use quieter electric mowers and leaf blowers, rather than loud, gas-powered models.

Muting the clamor

Ron Terry, a spokesman for Zion National Park, agreed that parks have some tools at their disposal to cut the clamor.

For instance, generators are restricted in the campgrounds. And to meet visitors' needs, 91 of the Watchman Campground's 160 sites have electrical hookups so generators won't be needed.

In 2000, the park began running a shuttle to keep cars and trucks out of the canyon.

"It has really changed the sound environment in the canyon, and we get a lot of comments about that," Terry said.

"When you go into the canyon now, you can hear the wind in the leaves, you can hear the sound of the river, you can hear the birds singing, sounds that would have been impaired."

Bloomberg offered a plan of attack for reducing sound litter in the parks. At the top of the list: launching a quiet awareness campaign.

While we don't treat noise as pollution, and we have come to accept it as a kind of cost of living, noise may well be the best place to start a 21st century anti-litter campaign, he said. And the national parks are a natural place to kick it off.