Sloths have specific calls for when they are looking for a mate. They also have a general, high-pitched call that sounds like "ahh-eee" and gives the three-toed sloth one of its common names: the ai.
Female sloths are very vocal when they are in heat, and they will scream in the jungle canopy until they are approached by eager males who will fight one another for a chance to mate. Sound transmits well in the jungle, allowing these generally solitary animals to find one another despite great geographic distances.
The sloth's "ahh-eee" call, on the other hand, is not associated with breeding.