Ultrasonic
Not to be confused with supersonic, something moving faster than the speed of sound.
An Ultrasonic waveform has a frequency too high to directly hear. It repeats more than about 20,000 times a second, known as 20 kHz.
Contrast with infrasonic frequencies, below about 20 Hz, and sonic frequencies, between about 20 Hz and 20 kHz.
Frequency ranges: Infrasonic | Sonic | Ultrasonic
