Owls make loud and soft hoots, screeches, rattling calls and quieter, two note calls. Some owls, such as the Sunda scops owl, give a whooping call.
Great horned owls give a classic, hooting owl call, which is loud enough to be heard for miles. The calls of this owl proclaim its territory and attract mates. The bird also screeches, when it snatches up its prey.
The song of a burrowing owl is a two-note cooing, but it also gives rattling and clucking alarm calls. The tiny screech owl does not actually screech, but makes urgent, trilling calls. A pair of owls often sing together.