among some nonhuman animals, the use of sound frequencies above the range of human hearing (i.e., above 20 kHz) for communication. Ultrasonic communication is commonly used by bats and dolphins, in which echolocation is important for navigation or finding prey. High-frequency signals do not travel very far, but, because of their short wavelength, they can provide excellent information about the location of prey and other objects in the environment. Compare infrasonic communication.