Noise created by humans is pervasive in US protected areas

Noise created by humans is pervasive in US protected areas
Acoustic recording station at the iconic tourist attraction Alcatraz Island in San Francisco Bay, Golden Gate National Park, California. Credit: United States National Park Service

Protected areas in the United States, representing 14 percent of the land mass, provide places for respite, recreation, and natural resource conservation. However, noise pollution poses novel threats to these protected areas, according to a first-of-its-kind study from scientists at Colorado State University and the U.S. National Park Service.

Researchers found that noise was twice as high as background levels in a majority of U.S. protected areas, and caused a ten-fold or greater increase in noise pollution in 21 percent of protected areas.

The often-overlooked impacts of noise, driven by expansion of human activities and transportation networks, are encroaching into the furthest reaches of remote areas, according to the study. The research findings highlight the pervasiveness and identify the primary drivers of noise in protected areas.

Rachel Buxton, lead author and post-doctoral researcher in the Department of Fish, Wildlife, and Conservation Biology in the Warner College of Natural Resources, said the team was surprised by how prevalent noise pollution was in protected areas.

"The we found can be harmful to visitor experiences in these areas, and can be harmful to human health, and to wildlife," she said. "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."

Noise created by humans is pervasive in US protected areas
United States National Park Service staff set up an acoustic recording station as a car passes on Going-to-the-Sun in Glacier National Park, Montana. Credit: United States National Park Service

Anthropogenic, or human-caused, noise is an unwanted or inappropriate sound created by humans, such as sounds emanating from aircraft, highways, industrial, or residential sources. Noise pollution is noise that interferes with normal activities, such as sleeping and conversation. It can also diminish a person's quality of life.

Measuring noise pollution is a challenging task, given its diffusive nature and since sound is not easily monitored remotely over large spatial scales; it can't be measured by satellite or other visual observations. Instead, for this study, the team analyzed millions of hours of sound measurements from 492 sites around the continental U.S. The results summarized predictions of existing sound levels, estimates of natural sound levels, and the amount that anthropogenic noise raises levels above natural levels, which is considered noise pollution.

How prevalent is noise pollution in protected areas? The research team found anthropogenic noise doubled background sound levels in 63 percent of U.S. protected areas, and caused a ten-fold or greater increase in background levels in 21 percent of protected areas.

In other words, noise reduced the area that natural sounds can be heard by 50 to 90 percent. This also means that what could be heard at 100 feet away could only be heard from 10 to 50 feet.

This reduced capacity to hear natural sound reduces the restorative properties of spending time in nature, such as mood enhancement and stress reduction, interfering with the enjoyment typically experienced by park visitors. Noise pollution also negatively impacts wildlife by distracting or scaring animals, and can result in changes in species composition.

Noise created by humans is pervasive in US protected areas
Median noise exceedance (the amount that anthropogenic noise increases sound levels above the natural level) in protected area units across the contiguous United States. Noise exceedance of 1.25, 3.01, 6.02, and 10 dB corresponds, respectively, to 25, 50, 75, and 90% reductions in listening area (the area at which an acoustic signal can be detected) for humans. Gray areas are outside the protected area network. Credit: R.T. Buxton et al., Science (2017)

High levels of noise pollution were also found in critical habitat for endangered species, namely in endangered plant and insect habitats. "Although plants can't hear, many animals that disperse seeds or pollinate flowers can hear, and are known to be affected by noise, resulting in indirect impacts on plants," said Buxton.

The study also revealed that high noise pollution levels within protected areas were in specific locations, where noise reduction techniques may best be targeted. The biggest noise-causing culprits were roads, aircraft, human development, and resource extraction.

Some protected areas have introduced effective techniques to reduce noise, launching shuttle services to cut back on traffic, implementing quiet zones where visitors are encouraged to quietly enjoy protected area surroundings, and creating noise corridors, aligning flight patterns over roads.

"Numerous noise mitigation strategies have been successfully developed and implemented, so we already have the knowledge needed to address issues," said George Wittemyer, an associate professor at Colorado State University and the senior author of the study. "Our work provides information to facilitate such efforts in respect to protected areas where natural sounds are integral."

Researchers said that many people don't really think of as pollution. But the team is hopeful that more people will consider sound as a component of the natural environment.

"Next time you go for a walk in the woods, pay attention to the sounds you hear—the flow of a river, wind through the trees, singing birds, bugling elk. These acoustic resources are just as magnificent as visual ones, and deserve our protection" said Buxton.

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More information: "Noise pollution is pervasive in U.S. protected areas," Science, … 1126/science.aah4783
Journal information: Science

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May 04, 2017
I don't see this getting any better simply because my experience has been that so few people believe noise pollution is real. Even though is has become all-pervasive in a huge amount of our envorinment most people seem to think it's quite alright. With the encroachment of larger and larger populations it will continue to erode the quiet of wilderness areas and grow in developed areas. We humans are a rather sad lot, aren't we?

May 04, 2017
Even at the personal level, noise from the endless manic froth that is commercial radio is pervasive. From cars and workplaces, worksites and neighbours. Why do so many in society feel the need to have constant loud stimulation, and asking them to tone it down gets the same response as if you'd asked to take a piss on their kitchen floor. Oh I'm sorry, was my quite personal space bothering you? Can I turn up my silence to 11, and show the same level of consideration they show for us?

May 04, 2017
I hunt, camp, raft, hike in Colorado. ATV/OHV noise is a BIG problem in National Parks & BLM land. They should be outlawed except for specific uses. Not go-carting on forest roads.
Uses could include ranching, game recovery, search & Rescue.

May 04, 2017
In the city suburban & urban; we should seek ways to avoid/minimize sirens (fire, police, EMT). Technology should focus on vehicles having warning noise & lights in the cab transmitted by the emergency vehicle within establish range & directions. These emergency vehicles could also control traffic lights remotely. I do not need to hear sirens in my home at all hours.

May 04, 2017
And if you look at the other extreme, to noise in the wilderness, I always suspected noise in the city contributes to crime. Isn't it proportional? More noise in the cities, more crime? I think the impact of noise pollution is worth more study if nothing else.

May 05, 2017
Why do so many in society feel the need to have constant loud stimulation
because the stimulation prevents them from thinking?


In the city suburban & urban; we should seek ways to avoid/minimize sirens (fire, police, EMT)
i disagree

for starters, far, far too many people are crap drivers (or ignore them). it is a law to yield right of way to an emergency vehicle running code (be it 2 or 3) and yet you can see in every state that there is a real problem with people doing that (accident statistics show that one)

and it's not uncommon to see pedestrians with ear jacks in listening to stuff, be it a phone call or music

sirens on emergency vehicles are there for a purpose
the only reason we should ever remove them is when there isn't a need - like Advanced AI vehicles which can take the human driver out of the equation or can rapidly avoid pedestrians and their irrational decisions

May 05, 2017
This is terrible. President Trump should implement new protected areas across the west and east coasts (which suffer the most noise pollution) and tax those municipalities with offending noise levels. That'll learn em.

May 05, 2017
How could this article not mention highly invasive industrial wind turbines, which add noise pollution and blatant visual disruption to areas that other energy sources tend to skip? Wind power is literally the biggest blight on many rural landscapes now. Animals are never polled about the effects of these aesthetic nightmares, and people are suffering in many rural areas.

On top of that, wind turbines have very questionable net carbon reduction, considering the huge fossil fuel component of their fabrication, road building, clear-cutting, installation and maintenance. It's very disheartening to see GreenFolk ignore the obvious blight when these terrible contraptions are built. I almost forgot to mention the light pollution they inject into night skies.

May 07, 2017
But the original angst is itself produced by a paternal pheromone deficiency, which is easily remedied. Musical thrill seeking, fireworks thrill seeking, gunfire thrill seeking: everything that disturbs the peace, basically, results from paternal facial sebaceous secretion pheromone deficiencies. Collect 250mg of the paternal facial skin surface lipid pheromone and give it to the music-loving culprit by mouth, and viola, no more violations of tranquility.
studies? links? references?

sounds rather far fetched to me considering the complexity of the human biome alone means fluctuations in the microbiome in the gut can influence mood

and that doesn't even consider psychotropics or neuropharmacology...

then there is this to consider: http://rspb.royal...full.pdf

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