there's an owl in the tree right outside my window making owl noises.

WOW don't you just love them? I love how you go out and you can just see the silhouette sitting there and you make a noise and you see it turn and look at you! And then they fly off with their huuuuuuge wings.

But they never make 'hoot hoot' noises. Always just 'tweet' sorts of things. How come people associate 'hooting' with owls when they never hoot?