Ultrasonic

Sound at frequencies above the audible range, i.e. above about 20 kHz.

Biological effects of ultrasound:

• Thermal – tissue is damaged due to heating
• Nonthermal – tissue damage due to mechanisms other than heating. These include mechanical forces on or within the tissue.
• Cavitational mechanisms – microstreaming, shock waves and microjets
• Non-cavitational mechanisms – radiation force, radiation torque and acoustic streaming

See also: Sound, Ultrasonic Testing.