Median noise exceedance (the amount that human noises increase sound levels above the natural level) in protected area units across the contiguous United States. Percent reduction in listening area refers to the reduction in distance at which a person can hear natural sounds due to noise pollution. Gray areas are outside the protected area network. Graphic: R.T. Buxton, et al., 2017 / Science

By Sarah Kaplan
4 May 2017 (The Washington Post) – In wintertime, the sounds of nature are so subtle they’re almost imperceptible: The whistling of the wind though craggy mountaintops, the whispering branches of the trees; the soft, delicate patter of an unseen animal’s paws across snowy ground. “It’s a really quiet experience,” said Rachel Buxton, recalling a recent winter hike in southwest Colorado’s La Garita Wilderness. “You’re almost hearing your own heartbeat.” But every 30 minutes, a jet flew overhead, shattering the fragile calm. “It’s shocking, right?” she said. “You’re in the middle of nowhere, yet you still can’t escape the sounds of humans.” That’s the trouble with noise pollution, continued Buxton, an acoustic ecologist at Colorado State University: “It really doesn’t have any boundaries. There’s no way of holding it in.” This problem pervades wilderness areas across the United States, Buxton and her colleagues reported Thursday in the journal Science. Using a model based on sound measurements taken by the National Park Service, they found that human noises at least double the background sound levels at the majority of protected areas in the country. This noise pollution doesn’t just disrupt hikers; it can also frighten, distract, or harm animals that inhabit the wilderness, setting off changes that cascade through the entire ecosystem. [more]

Human noise pollution is everywhere, even in the national parks

ABSTRACT: Anthropogenic noise threatens ecological systems, including the cultural and biodiversity resources in protected areas. Using continental-scale sound models, we found that anthropogenic noise doubled background sound levels in 63% of U.S. protected area units and caused a 10-fold or greater increase in 21%, surpassing levels known to interfere with human visitor experience and disrupt wildlife behavior, fitness, and community composition. Elevated noise was also found in critical habitats of endangered species, with 14% experiencing a 10-fold increase in sound levels. However, protected areas with more stringent regulations had less anthropogenic noise. Our analysis indicates that noise pollution in protected areas is closely linked with transportation, development, and extractive land use, providing insight into where mitigation efforts can be most effective.

Noise pollution is pervasive in U.S. protected areas