The term echolocation is formed from two concepts, echo and location. In this way, we speak of echolocation to express the ability to perceive space from the perception of sound waves that are generated in it.

This faculty is characteristic of some animals such as the bat or the dolphin. Bats orient themselves with absolute precision in the dark thanks to this sense.

This system allows them to hunt insects that are invisible to other animals and move with little use of sight. In the case of dolphins, they have an extremely sensitive sonar system that allows them to move through the deep sea, hunt for prey and avoid obstacles. Both the bat and the dolphin emit bursts in the form of sound impulses and this allows them to obtain information from the physical space that surrounds them (the return of the echo is what gives them all the information).

Many species of bats use echolocation to orient themselves and determine the size, speed, and direction of their prey. It produces ultrasonic sounds from the larynx, emitted from the nose or mouth, although the mechanism of production is not known. Their sounds for echolocation are in the 20-100 kHz band.

Since sound travels much faster through water than in air, echolocation is one of the most important senses for members of the suborder Odontoceti.

Dolphins emit rapid sets of ultrasonic pulses when they locate prey. It does not matter if your potential food is too agile or if the waters are very dark or cloudy, echolocation allows you to identify the size, shape, composition, speed and direction of the prey; consequently, dolphins are able to learn the type of echo that certain animals emit, with which they can recognize their favorite prey.

The dolphins click and wait for the echo to return (echo delay). The time between two clicks is shorter as the dolphin approaches its target (Hughes, 1999). There are experiments that show that the echo delay is constant in time if we put an object at a constant distance. If we remove the object, the echo delay does not change (Au, 1993). The duration of the clicks is 70-100 microseconds.