Planes and vehicles main culprits masking iconic natural sounds in peaceful national parks

U.S. national parks are full of natural sounds. In Rocky Mountain National Park, visitors might hear the bugle of elks. At Yellowstone National Park, wolves howl in the distance. Iconic sounds like these are often associated with specific parks, creating unique soundscapes and enriching visitor experiences. When you add human-made noise to the mix, however, these sounds are at risk of being drowned out.