There's a short article by Clive Thompson in the June 2008 issue of Wired that I thought was interesting. It was a quick look at Bernie Krause's work at recording the sounds of nature, or as he coins it, "biophony."

Wired doesn't seem to have the article on its website, but here's another short article that sums up the idea:

Biophony: Ecological Soundscapes
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