Objects buried in the ocean sediment are also "visible" to the echolocation system. Importantly, it can function in both the quiet and the noisy ocean environment.

The echolocation system is divided into three major subsystems: transmission (by tissues in the melon), reception (by the teeth and lower jawbone), and signal processing/decision making (by the brain).

The echolocation system is not functional in the newborn calf. Consequently, the mother will "steer" the calf away from objects which could cause it harm. Often, in captive environments, calves are born in "structureless" pools which protect them from inadvertent injury. A calf begins to show signs of transmitting echolocation clicks as early as 2 months after birth. The more complex the environment in which a dolphin finds itself, the more complex the echolocation signals emitted. The size, shape, direction, speed, distance and composition of an object as small as a ping pong ball as far away as a football field (100 yards) can be detected by the dolphin’s echolocation system. Echolocation may also function socially as a method of identification between mother and calf or between individuals within a pod.

Although research on echolocation is extensive, much of our understanding of it remains a mystery. Dolphins produce echolocation sounds that are either harmonic or pure in tone and are of changing frequency. A "train of clicks" is produced in echolocation. Each click in the train is of very short duration. Anywhere from 8 to 2,000 echolocation "clicks" may be emitted per second. This short duration allows the click to go out, strike an object and return to the animal before another click is produced. This prevents the mixing or confusion of click signals received by the dolphin. The time between clicks in a particular train changes as the animal approaches an object, as it must adjust for distance to its target. Short duration, high frequency clicks also allow it to focus on small fish and small obstacles, but they don't travel as far in water as do low frequency sounds. That is why communication between marine mammals is usually done with sounds of low frequency. A dolphin may turn its head from side to side when echolocating to provide further information about the target size and direction. When used to stun fish for feeding, echolocation clicks may be produced as loud as a booming 230 decibels, representing some of the loudest sounds made by animals in the ocean. It has been shown, though, that if a dolphin’s eyesight is impaired (by covering its eyes) its echolocation system is less effective, proving that echolocation and eyesight work in tandem. Recent research suggests dolphins can "eavesdrop" on other dolphins' echolocation returns, at times stealing a fish from a competitor. Recent studies show dolphins have the ability to echolocate an object within another object. In other words, when an object of one density is placed inside an object of lesser density, the dolphin can visualize the interior object (much like ultrasound).