Some scientists suggest that sound is emitted from a nasal plug and that the shape of the melon is altered by muscles to focus sound. Other scientists believe that the larynx emits sound and argue that echolocation focusing is achieved by bouncing sound off various parts of the skull. Whales use echolocation mainly for navigation and hunting. The cetacean environment is often dark and hard to see in. Echolocation provides whales a way to gather information about objects and prey around them including their range and configuration.
Echolocation is extremely sensitive.
Echolocation is so sensitive that some cetaceans, like river-dolphins , may use echolocation in place of sight. Scientists do not know. However, scientists do think that most toothed whales such as dolphins, river-dolphins, and porpoises can echolocate. This site was created by Laura Drumm and the National Marine Mammal Laboratory .