This article is a profile of Bernie Krause, one of many scientists (or bioacoustician as Krause calls himself) who studies the soundscape of different environments. This is a great way to explore environments and see what animals, flora, and other environmental impacts there are in any location.
The sad observation Krause makes is that the recordings he made of the same environments 40 years ago are much more rich and lush, and are now basically extinct. The diversity of sound, and therefore wildlife, as decreased dramatically.
I have had to do soundscape studies myself for different classes, and while the sounds are amazing and often beautiful, they also reveal incredible observations one normally wouldn’t have noticed about the frequency of use, type of use, and overall population in any given environment, among many other things.