Ultrasound

Ultrasound is sound that no one can hear, with f > 25 000 Hz. Ultrasound can be generated by blowing any whistle hard. Ask your dog or a bat what that sounds like.

High intensity ultrasound is used to break up stones within the body without surgery.

Low intensity ultrasound body-scans (f = 33 000 Hz) have become routine in hospitals as a non-invasive examination technique that avoids the use of ionizing radiation. Next time someone close to you has a baby, go and have a look at the little chap swimming around and sucking his thumb.

Outside

Inside

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