Dolphins use sound to identify objects around them, navigate underwater, hunt prey and communicate with each other. Through their well-developed sensory ability, they use echolocation by producing various sounds that reflect and echo back from objects.
Echolocation is a distinctive ability of dolphins, other marine mammals and bats to project high-frequency sound waves and listen for echoes when the sound waves bounce from objects. Dolphins echolocate by creating clicking sounds and using echoes to find out what objects surround them. They can determine the size, form, pace and direction of things with precision. Dolphins produce varying types of sounds, such as clicking, squeaking, creaking and buzzing. They produce sounds in different volumes, wavelengths, patterns and frequencies.
The fast conduction of sound in the water makes echolocation highly effective. Dolphins use the nasal sacs in their heads to produce a rapid series of clicks, which go through their protruding forehead. Dolphins interpret the reflected sound wave as they receive the information through their fat-filled cavities in the lower jaw. Their auditory nerves deliver the information to the middle ear and brain, resulting in an acoustic image.
Dolphins also generate sounds to communicate above the water as they jump or hit the water surface with their flippers and flukes. Scientists believe that dolphins use sounds to recognize each other and communicate tactical signals while hunting food as a group.