The loudest and quietest places in the United States have been mapped, providing a detailed look at noise levels around the nation. A total of 1.5 million hours of acoustical monitoring were analyzed to produce the new map, which could have implications for wildlife protection.
New York City was found to be the noisiest location in the United States, and Dinosaur National Monument in Colorado was found to be the quietest. Background sound levels averaged 20 decibels (the same noise level as a whisper) or lower at The Great Sand Dunes National Park in The Centennial State, as well as areas of Yellowstone National Park. In some cities, background noise averaged between 50 and 60 decibels, about equal to a normal conversation between two people.
Researchers accounted for noise from street traffic, as well as air quality, in order to refine their measurements.
As might be expected, the loudest background sound levels were measured along the Atlantic coast of the northeast, along with the northern half of the Midwest, Florida, and the Gulf and Pacific coasts. Most western states were among the quietest regions nationwide, although cities stood out here as well.
Some animals have hearing far superior to that in humans, and the proliferation of human-generated noise could affect these animals to a far-greater degree than people. Owls and bats depend on hearing in order to hunt, and artificial noise could disrupt their ability to hunt.
The National Park Service is already utilizing the new map to predict and measure the effect of sound levels on wildlife around the nation.
Extremely high noise levels can harm human hearing, as roughly one-quarter of the 40 million Americans diagnosed with hearing loss suffers from noise-induced hearing loss (Nihl). Dangerous levels start at around 85 decibels, about as loud as sitting inside a bulldozer while it idles. That noise level can cause hearing damage after just eight hours. Music played through headphones at maximum volume plugged into a powerful stereo can reach 100 dB, and thunder from a nearby bolt of lightning can reach 120 dB. The amount of time a person spends listening to a sound also plays a role in potential damage.
Animals, even house pets, can react poorly to loud sounds. Because of this, people living with cats and dogs need to be aware of how their companion animals react to storms, loud parties or music.
Examination of noise levels around the country was presented at the 2015 annual meeting of the
American Association for the Advancement of Science (AAAS).