The great outdoors is getting noisier

Yosemite National Park. Photo by Jerri Riffel, Flickr.

It’s getting louder every day.

And Gordon Hempton decided to do something about it. He has spent the past 30 years traveling around to quantify the racket. As Newsweek reported in a story about Hempton last week, the audio ecologist claims that, during daytime, the average noise-free interval in wilderness areas has shrunk to less than five minutes. And according to Newsweek:

[Hempton] says there are fewer than a dozen places of silence — areas "where natural silence reigns over many square miles" — remaining in America, and none in Europe.

For example, in 1983 Hempton found 21 places in Washington state with noise-free intervals of 15 minutes or more. By 2007 there were only three.


Now let’s say that you want some peace and quiet. You might head out to one of our national parks. But guess what: The decibel count is on the rise there, as well. I spoke with Karen Trevino, who manages the National Park Service’s natural sounds program. Based in Fort Collins, Colo., she works with Park Service acoustics experts like Kurt Fristrup.

They told me that helicopters and airplanes are major sources of noise in the parks. They said that the Federal Aviation Administration has forecast that over the next ten years the number of national park air tours will grow from 180,000 to nearly two million.

Recently, Karen said, the Park Service is receiving more and more complaints about motorcycle noise from “after-market” exhaust systems. There are a number of these products, featuring names like “Screaming Eagle.” As such names imply, these devices are installed with the express purpose of making the vehicle louder.

That means that you are less likely to hear bird songs, wind, waterfalls, rustling leaves, or the howling of a wolf.

That’s bad enough. But imagine for a moment that you’re a great grey owl. Your hearing is so good that you can hear a mouse under a foot of snow. Once you do, you can dive down to snatch him.

But when the sounds of mice are masked by all the unnatural noise that society manufactures today, the owls’ ability to find enough food is compromised. Research is also showing that some birds are changing their mating songs because of noise. Wildlife biologists who initially thought that noise was not a cause for much concern are finding in their studies that this is, in fact, a serious threat.

Snowmobilers disrupts bison in Yellowstone National Park, Wyoming. Photo by Irene Owsley Spector.If you’ve ever visited Yellowstone in the winter, you probably heard the roar of snowmobiles. In addition, you probably smelled—and saw—the exhaust that they spew. It got so bad that many park rangers at the main entrance were wearing gas masks. Picture that.

The Wilderness Society has worked with scientists and other partners to persuade the federal government to reduce the number of these machines allowed in Yellowstone. We believe that they should be phased out. A much quieter and cleaner alternative is the snowcoach, which can carry a number of visitors.

If you’d like to learn more about the sounds of silence in our natural cathedrals, you can read my interview with Karen and Kurt, which appeared originally in our magazine, Wilderness.

Yosemite National Park. Photo by Jerri Riffel, Flickr.
Snowmobilers disrupts bison in Yellowstone National Park, Wyoming. Photo by Irene Owsley Spector.