Toothed whales like dolphins and porpoises have single blowholes on their melons, whereas true (baleen) whales have two. The melon houses, among other things, many small air sacs which are used to produce click vibrations. These vibrations pass outward through the salt water, strike an object and bounce back for interpretation. The melon is able to focus its "beam" of clicks toward objects of interest. This process of object size, shape, distance, thickness and direction identification is called echolocation (see the "echolocation" section of this site for further information). These click vibrations return to the animal's teeth, which act like antennae to collect the sound waves and pass them to the lower jaw bone. They collect within a fatty area in the lower jaw bone, where they are then sent to the inner ear bones and on to the brain via the auditory nerve. The dolphin’s echolocation system can identify an object as small as a ping pong ball as far away as 100 yards.

In addition, the various colorful patterns on the dolphin’s melon, along with the animal’s fin structure and signature whistle, serve to identify individual dolphins.