ULTRASOUND
Ultrasound
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' 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 in healthy, young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.The above text is a snippet from Wikipedia: Ultrasound
and as such is available under the Creative Commons Attribution/Share-Alike License.
ultrasound
Noun
- sound with a frequency greater than the upper limit of human hearing; approximately 20 kilohertz
- The use of ultrasonic waves for diagnostic or therapeutic purposes
The above text is a snippet from Wiktionary: ultrasound
and as such is available under the Creative Commons Attribution/Share-Alike License.