The organ in a toothed whale’s head that helps focus echolocation clicks is the melon.
The melon is a rounded mass of specialized fatty tissue in the forehead, between the blowhole and the tip of the snout. It is part of the whale’s nasal sound-producing apparatus and acts somewhat like an acoustic lens, helping shape and direct outgoing vocalizations.
Its internal fats vary in composition, so sound travels through different regions at different speeds. That gradient can refract and focus sound as it leaves the head. The melon is found in toothed whales, including dolphins, porpoises, sperm whales, and beaked whales; baleen whales do not use this same echolocation system.
The melon is often confused with the spermaceti organ of sperm whales, but they are distinct structures. In belugas, muscular control can visibly change the melon’s shape.