The great natural areas of America are being threatened by increasing levels of noise pollution, according to recent research in the magazine Science. Noise has doubled for more than half of all protected areas, ranging from local reserves to national parks spanning over millions of acres to local parks. This bad news for local wildlife, as well as humans.
Studies on Sound Levels in National Parks
Led by researcher Rachel Buxton, a conservation biologist at Colorado State University (CSU), sound levels were analyzed from nearly 500 protected areas around the US. The data was then combined with other factors such as measured distance from roads, and elevation, creating a model able to predict expected noise levels in national parks. This computer model was applied to natural areas, large and small across the nation. The scientists then considered and compared two scenarios: protected areas with the manmade noise, and without.
They found that in over half of the areas surveyed, manmade noise overrides natural noise to an extent that the amount of distance needed to hear the natural sound is halved. In other words, you would have to get twice as close to hear the sound of the distant eagle overhead than you would otherwise have to, had there been no manmade noise. This means that sound pollution has doubled in 63% of protected areas, rising to a ten-fold increase in some 21% of areas surveyed.
“We were surprised we found such high levels of noise pollution in such high numbers of protected areas,” remarked Rachel Buxton, commenting on the scale of the problem at hand.
Noise Pollution is a Growing Problem
As to be expected, parks in urban areas were the most likely to be affected by noise pollution. Traffic from cars and trucks are at most to blame for the higher levels of noise in these places. But other areas for concern were the natural areas that have been opened up to industry by state and federal government. These areas were exposed to sound from oil and gas extraction and other industries.
What can account for this rise in noise pollution? The Federal government introduced the Noise Control Act In 1972 which gave the Environmental Protection Agency (EPA) the ability to impose limits on noise from cars and industrial machinery. But crucially, noise in more protected areas has largely been ignored. The decision to let noise pollution in protected areas slide is puzzling when you consider that these natural areas cover almost 14% of our entire country. We can speculate that this is the main reason why noise pollution has increased.
The excess noise has larger effect than just annoying park patrons. Co-author George Wittemyer, also of CSU, said the study showed some areas to have “shockingly high levels that can potentially be bad for human health,” These noise levels can undo all of the benefits of being in nature, such as an improved mood and memory retention.
It’s also bad news for wildlife. Some animals need silence so that their calls to potential mates can be heard. If a bird’s song can only be heard in a 10 meter-radius rather than the 100-meter radius they are used to, then long-established mating rituals are disrupted, which could jeopardize entire species of wildlife.
Conserving the Serenity of National Parks
The good news is that the study shows that many areas are still largely protected and the natural sounds we associate with the great outdoors are still intact in many large natural areas. But as the din of urbanization continues to spread, the danger is that it is encroaching closer to quiet areas with each passing year.
It is up to federal and state departments to think carefully about how to conserve the serenity of the great outdoors for future generations. Some measures are already in place, such as operating bus shuttles in natural areas to reduce traffic, or funneling highways and flight paths into “noise corridors.”. It is with this research that Buxton hopes that policy-makers will take potential noise pollution in protected areas into consideration when faced with the lure of industry, and the desire to make all areas of our nation accessible by car.
Visit Us at Denver Audiology
Sound is an incredibly important part of our lives – and though we would prefer not to be inundated with noise pollution, our access to everyday sounds like conversation and music are important to our well-being. If you’ve been experiencing changes in your hearing, contact us at Denver Audiology today for a hearing test!