Compare ultrasonic and infrasonic waves?
ultrasonic means their frequency is too high for us to hear, infrasonic means their frequency is too low for us to hear. This is analogous to the electromagnetic spectrum, where ultraviolet light has too high a frequency for us to see, and infra-red light has too low a frequency for us to see.
Ultrasonic and Infrasonic sound waves are waves that are not audible to human beings. The audible region contains sound waves of 16 Hz to 20,000 Hz. Infrasonic sound waves have frequencies below 16 Hz. For example, an earthquake. Ultrasonic sound waves have frequencies above 20,000 Hz. For example, x-rays. Grade 11 Physics