As a result, as the dolphin swims, it moves its head back and forth. This movement allows the dolphin to scan its surroundings while the echo the dolphin has sent out bounces off objects and hits the dolphin s lower jawbone. The lower jawbone conducts the returning sound waves into the inner ear. The pitch of the echo, and the time it takes to return to the dolphin, allows the dolphin to be able to determine the shape, size, speed, texture, and density of the object. Dolphins also communicate by other means of sounds.
Dolphins communicate by breaching too.
Breaching is when the dolphins jumps into the air and falls back into the water with a loud splash. Also, when they hit their tail or pectoral fin on the water s surface. The hearing capability of a dolphin is more sensitive than a human. They can detect sounds up to 200,000 Hertz. A Hertz is the number of vibrations per second.