Read this wonderful piece on the work of researchers recording the natural sounds of national parks all across the U.S. With more than 70 soundscapes so far, the scientists share that escaping anthropogenic sound is difficult (big surprise), and that, in some cases, the presence of human sound has had impacts on the ecosystem. In fact, certain wild sounds are becoming harder and harder to find, either due to human-made sound pollution itself, or the other impacts human development has had on the natural environment.
I'm reminded on John Cage's stance on conservation of natural sounds, and on the sonic opportunities we miss if we fail to save them. One of the researchers who has been recording soundscapes for the project agrees. "If we start to lose sounds of wilderness, we start to lose a piece of us," he said. "And that really hits at a place that we don't fully understand, but which is important."
Definitely worth the read: http://www.npr.org/2016/06/29/483241647/beyond-sightseeing-youll-love-the-sound-of-americas-best-parks?utm_source=twitter.com&utm_campaign=health&utm_medium=social&utm_term=nprnews
Be sure to check out the great model of sound intensity across the US from the National Park Service.