Definitions for ultrasonicsˌʌl trəˈsɒn ɪks
Random House Webster's College Dictionary
ul•tra•son•ics*ˌʌl trəˈsɒn ɪks(n.)
the study of the effects of sound waves having wavelengths above the limits of human perception.
* (used with a sing. v.).
Origin of ultrasonics:
the science and technology of ultrasound
U.S. National Library of Medicine
A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.