@mathewi There is an unbelievably beautiful (and sad) episode of 20 Thousand Hertz about whale song, and how human noise pollution is causing them to sing above their natural tone in order to keep communicating. It’s really worth listening to. One of my favorites ever. https://www.20k.org/episodes/underthesea
20,000 dBs Under the Sea — Twenty Thousand Hertz – The stories behind the world’s most recognizable and interesting sounds.