I recall an old show where they used the microphone systems left over from the cold war submarine watching days. They used it to listen/track whales, etc.
At one point they gave some short samples. “This one is a Beluga whale off the coast of Alaska. This one is a sperm whale off the coast of California....”
The last one they played sounded both organic and digital at the same time - like something from a cheesy sci-fy alien movie.
“This one is from 4 miles down in the Mariana Trench. We have no idea what it is.”