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Ultrasound is sound with frequencies greater than 20 kilohertz. [1] This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz.
[citation needed] Exposure to more intense ultrasound over 140 dB [citation needed] near the audible range (20–40 kHz) can lead to a syndrome involving manifestations of nausea, headache, tinnitus, pain, dizziness, and fatigue, [24] but this is around 100 times the 100 dB level cited above, and is generally not a concern. Dr Joseph Pompei of ...
Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound.
Derivative of Heath Raftery's own creation. Rough diagram of sound frequency scale, showing ultrasound and some applications. Date: 28 June 2010, 23:30 (UTC) Source: Ultrasound_range_diagram.png; Ultrasound_range_diagram_png_(sk).svg; Author: Ultrasound_range_diagram.png: The original uploader was LightYear at English Wikipedia.
Ultrasonic vocalizations are not precisely 22-, 40- and 50-kHz. 22-kHz calls can range from 18-32-kHz, 40-kHz calls range from 40-70-kHz, and 50-kHz calls range from 35-72-kHz. [8] The 22-kHz vocalizations of adults and the 40-kHz vocalizations of pups are emitted in response to aversive situations or noxious stimuli. [8]
Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimeters (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to ...
This method of medical ultrasound therapy can be used for various types of pain relief and physical therapy. In physics, the term "ultrasound" [1] applies to all acoustic energy with a frequency above the audible range of human hearing. The audible range of sound is 20 hertz – 20 kilohertz. Ultrasound frequency is greater than 20 kilohertz.
Ultrasound can ablate tumors or other tissue non-invasively. [4] This is accomplished using a technique known as high intensity focused ultrasound (HIFU), also called focused ultrasound surgery. This procedure uses generally lower frequencies than medical diagnostic ultrasound (250–2000 kHz), but significantly higher time-averaged intensities.