What is the term for sound waves above human hearing range, typically above 20,000 Hz?

The term for sound waves that exist above the human hearing range, typically above 20,000 Hz, is ultrasonic. Ultrasonic waves are those frequencies that are higher than what humans can detect, which makes them useful in various applications such as medical imaging (ultrasound), cleaning delicate items, and in some pest repellents.

In contrast, sonar refers to sound navigation and ranging, which typically involves sound waves in the audible range or sub-audible range, often used in underwater exploration. Infrasonic refers to sound waves below the human hearing range, generally below 20 Hz, while auditory is a term that relates broadly to the sense of hearing but does not specify the frequency range. Therefore, ultrasonic is the correct and specific term that denotes sound waves above human hearing capacity.