.......Dolphin echolocation differs from that of bats in several aspects. Their click-like calls are normally much shorter in duration than the tonal airborne signals used by bats. These short calls may be necessary due to them producing good temporal resolution in water; a medium where sound travels five times faster than in air.

.......The acoustic images perceived by dolphins are likely not comparable to that of bats. Water has a greater density and is less compressible than air, giving it greater acoustic impedance. The skeletons and swim bladders of fish may stand out to a dolphin, as their impedance would mismatch that of water. Dolphins can even use this mismatch to detect prey under sediment [1].

.......Like bats, dolphins have a system of automatic gain control in place. Whereas bats alter the gain of the sonar receiver, dolphins opt to alter the sonar transmitter. The amplitude of the sonar dolphins emit decreases 6 dB every time the travel distance is halved. The rate at which dolphins emit clicks rises as it closes in on a target. It is speculated that dolphins decrease the click amplitude as the emission rate increases. This overall strategy is superior for dolphins because the muscles in their middle ear are stiffer and denser than in bats, making them less adaptable [4].

.......Dolphins produce their echolocating sound from within phonic lips in the nasal passages, transmit sound through a waxy melon on the forehead (for the purpose of removing the impedance mismatch with water), and receive echoes via their lower jaws [1]. For a diagram, refer to this figure.