When I was a kid we had neighbors with Peacocks. Twice. The first time I heard them, I thought it was a cat being tortured. I think it took several weeks before I realized what was going on. The second time didn't take as long, but it was still confusing until we figured out it was Peacocks again.
Beautiful birds, horrifying call.
It took me a while in that graveyard to figure out what it was, and I'm an adult :) A tortured cat is a good description.