Sound travels farther and faster in water than in air. As a result, marine animals, such as whales, can use sounds to talk with one another from far away. Other animals, such as shrimp, use sound to hunt.
When underwater, divers can struggle to locate the direction of the sound. On land, sound has time to enter the ears at different instances. Therefore, human brains can find out the direction of the sound more easily. In water, the sound will seem to be coming from directly overhead. While underwater, an open circuit diver will continually exhale gas. That sound is loud and reduces the diver’s ability to hear other sounds.