On February 17, researchers from National Parks Service’s Natural Sounds project released a map depicting the loudness of a typical summer day from coast to coast across the contiguous United States.

According to the map, which was released at the annual meeting of the American Association for the Advancement of Science in San Jose, California, the eastern half of the United States is louder than the west. And although the map includes natural sounds as well as human-made sounds, it is perhaps not surprising to see the cities and more populated areas showing up as loudest.

The researchers recorded 1.5 million hours’ worth of long term noise measurements at 546 sites across the U.S. To create the map, they combined these samples with information such as latitude and longitude, time of day and year, climate and moisture levels – wetter, more vegetative areas tend to be noisier than deserts.

Enjoying EarthSky? Sign up for our free daily newsletter today!

The researchers also predicted the loudness of a summer’s day in an alternate universe without people. Again, the East is louder overall. Much of what drives this difference, the researchers said, is water. A corridor along the Mississippi River stands out, as well as South Florida. As map co-author Daniel Mennitt says, “Sound is life, right?”

Bottom line: On February 17, 2015, at the annual meeting of the American Association for the Advancement of Science in San Jose, California, researchers from the National Park Service’s Natural Sounds project released a map depicting the loudness of a typical summer day from coast to coast across the contiguous United States.

Read more from the Society for Science

