Whales produce sounds inside their blowhole. Most of these sounds are ultrasonic, a higher frequency than humans can hear. Some whales, like the baleen whale, communicate through infrasonic, or low-pitched, sounds. These sound like whistling and clicking. The whistles are for communication and the clicks are for echolocation.
Whales are categorized into two groups: toothed whales and baleen whales. Toothed whales include porpoises, dolphins, killer whales and sperm whales. Toothed whales are fast swimmers and hunters. Baleen whales are filters feeders and include the blue whale, humpback whale, gray whale and bowhead whale.Learn more about Marine Mammals