Echolocalization in toothed whales

Dolphins and toothed whales use an echolocalization system called bio sonar, emitting calls out to the environment and listening to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Sounds are generated by passing air from the bony nares through the phonic lips. These sounds are reflected by the dense concave bone of the cranium and an air sac at its base. Most toothed whales use clicks in a series, or click train, for echolocation, while the sperm whale may produce clicks individually. Echoes are received around the lower jaw, from where they are transmitted to the middle ear via a continuous fat body.