When people want to disconnect from the chaos of city life, they go to nature. National parks and protected areas in the United States are supposed to offer a refuge, a safe space where one can find peace and quiet. Unfortunately, new research has shown that these places aren't so peaceful nor quiet anymore. The racket of human noise and activity has already invaded a good chunk of protected areas.

According to a report from Phys Org, researchers from the Colorado State University and the U.S. National Park Service discovered that noise pollution was twice as high as background sound levels in 63 percent of the protected areas in the country. This led to the massive increase in noise pollution -- as much as 10 times or greater -- in 21 percent of the protected areas.

Noise reduced the area where natural sounds can be heard by 50 to 90 percent. Now, sounds that could supposedly be heard at 100 feet could only be heard from 10 to 50 feet.

The results of their study surprised even the team, according to lead author Rachel Buxton of the Warner College of Natural Resources Department of Fish, Wildlife and Conservation Biology.

"The noise levels we found can be harmful to visitor experiences in these areas, and can be harmful to human health, and to wildlife," Buxton explained. "However, we were also encouraged to see that many large wilderness areas have sound levels that are close to natural levels. Protecting these important natural acoustic resources as development and land conversion progresses is critical if we want to preserve the character of protected areas."

By nature, it can be difficult to assess noise pollution. The team was able to get their results by studying millions of hours of sound measurements from 492 sites around the country.

Humans may be losing their sanctuary, but wild animals are losing their home. The researchers detected high levels of noise pollution in critical habitats for endangered species, particularly in places where endangered plant and insects thrive. Strange noises can interfere with the lives of wildlife, distracting or scaring them and covering up the natural noises that can be crucial to their survival.

The research has been published in the journal Science.