Dolphins are highly intelligent and complex creatures that have a specialized set of organs that enable them to “see” using sound.

• Dolphins can emit a high–pitched series of clicks in a narrow beam directly in front of them. As the clicking sounds strike an object, such as a fish, some of the sound is reflected back as an echo to the dolphin, who can hear the sounds and perceive an image of the object or fish. The process is known as echolocation, and is the same principle used in SONAR ( SOund Navigation And Ranging) by submarines.
• The dolphin has some remarkable structures to produce the sound and to detect the returning echoes. In air chambers close to the blowhole at the top of a dolphin's head, there are a pair of lip–like membranes that the dolphin forces air through to produce sound. The membranes resemble the lips of a monkey and are sometimes referred to as “monkey lips.”
• At the front of a dolphin's head, just forward of the sound–producing membranes, there is a rounded dome–like structure known as the “melon” which is made of fatty tissue and oil. The dolphin uses it like a lens, contracting the attached muscles to amplify and focus the sound in a powerful, concentrated beam. The clicks are in a sound–range above the range of human hearing.