Ultrasound is an oscillating sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from 'normal' (audible) sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
All stories in Ultrasound
-
This 'Ultrasonic gripper' lets robots move things without touching them
When we think about robots working in factories and assembly lines, we often imagine large robotic arms moving heavy components ...
-
Brain science’s biggest roadblock: Collecting better data without killing people
Historically, there has been no safe, non-invasive and/or efficient method with deep penetration for modulating the human ...
-
How the hell does your phone's in-screen fingerprint scanner work?
If you've used an Android phone recently, you've probably come across the in-screen fingerprint scanner. But how does it ...