Alligators do not have external ears. However, alligators do have small slits behind their eyes. The slits help alligators hear by sending sound waves to their inner ears.
Alligators above water have similar hearing abilities to birds, lizards and other animals without external ears. An alligator's hearing is equal to a goldfish's, and the anatomy of alligators' ears gives them exceptional hearing while they are submerged underwater. An alligator begins to hear when vibrations travel through its skull to its eardrum. Above and below water, alligators are most sensitive to sounds about 800 Hz, which is the range of the chirps made by hatching baby alligators.