Ultrasound is sound with a frequency greater than the upper limit of human hearing (greater than 22.1 kHz).
Ultrasonic is an adjective referring to ultrasound.
Ultrasound and ultrasonic may also refer to:
Medical ultrasonography, an ultrasound-based diagnostic imaging techniqueUltrasound (band), a rock bandGravis Ultrasound, a sound card for the PCUltra-Sonic (band), a Scottish dance groupUltrasonic (film), an American independent filmUltrasonic sensors and transducers which use ultrasound to measure distance and velocityUltrasonic testing, a technique of non-destructive testingUltrasonic cleaningUltrasonic weldingUltrasonic motors, a type of motor that utilizes ultrasonic vibrations