As with their‚ dolphin‚ cousins, killer whales are extremely vocal‚ animals‚ and communicate between one another using clicks and whistles in a process known as echolocation. Killer whales are known to at their most vocal and noisy when the killer whales are hunting and the killer whales are much calmer and quieter when they are resting. Killer whales are known to use different sounds when the killer whales are participating in different activities.