Ultrasound Definition and 17 Discussions

Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and accelerating chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles.

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  1. loophole

    Water deformation subjected to ultrasound waves

    Hello everyone, in one of my projects I am dealing with the following problem: We have a tank filled of water. If we assumed that a focused ultrasond beam hit the water perpendicularly to the surface. How can I calculate the displacement of the water surface? In particular, I am interested in...
  2. F

    Audible sound range for beats

    Hi all, I recently came across an exercise observing that human cannot hear ultrasounds, but could hear the beat between two different ultrasounds, provided that its frequency falls in the audible range between 20 Hz and 20kHz. The problem gives one frequency and asks for the range of the other...
  3. vlada113

    Audio/Video Using ultrasound to create guitar effects

    Im interested in using ultrasound to intrfere with sound that comes out of guitar amplifier or sending ultrasound together with normal guitar signal in amp. My questions are : Is it possible? What will it do? Is there anything like it that i can look into? Thank you very much
  4. T

    How does the size between scatterers affect reflection?

    If a sound wave hits multiple scatterers spaced closer than the wavelength and moving fast but at different velocities how is the reflective beam is affected?
  5. T

    Reflection Coefficent in Ultrasound scan

    Homework Statement Discuss the main advantage and disadvantage brought about by a reflection coefficient being very small, and hence highlight the attributes that an ultrasound scanner must have to fully exploit very small boundary reflection. Homework Equations The Attempt at a Solution I...
  6. D

    Why does piezoelectric need amplifying?

    Homework Statement Descibe[/B] in detail the contruction of a piezoelectric device (ultrasound machiene) and how it works. And explain why the singal from that device need amplification Homework Equations The Attempt at a Solution Electrical current passes to the piezoelectric crystal...
  7. L

    Taking a photograph of sound

    Is there any sensor or method that allows a 'photo' to be taken of sound from different places? Similar to an ultrasound that is used in the medical field, but can be used more like a camera. I know about Schlieren Imaging but I'm thinking more like a map of all the sounds at a moment, maybe...
  8. M

    I Effects of Ultrasonic Transducer in contact with glass

    I'm looking for a way of using ultrasonic cleaning to clean the inside of a glass vessel filled with some sort of fluid by transmitting ultrasounds through the glass, rather than submerging the entire glass vessel. If an ultrasonic transducer, let's say something with a maximum frequency of 40...
  9. F

    A Rajlich's Hypothesis - Ultrasonic Cavitation

    'Rajlich's Hypothesis is a physical hypothesis with a significance for geology. There exist macroscopic white lamellae inside quartz and other minerals in the Bohemian Massif and even at another places in whole of the world like wavefronts generated by a meteorite impact according to the...
  10. H

    Acoustical absorption

    What is the formula to calculate acoustic absorption in water? particularly sound in the ultrasonic range.
  11. L

    Operating a portable ultrasound machine in -30 degrees C

    Dear friends. I am a cardiovascular health researcher writing on behalf of my research team based in Copenhagen, Denmark. We plan to conduct a high-altitude field study on cardiopulmonary function assesed by ultrasound on Aconcagua summit in near 7000 meters altitude. Reports say it will be...
  12. darklord27

    Can an Ultrasonic wave penetrate a LPG cylinder

    Hey guys, First time poster here. Presently I'm doing a project to measure the levels of LPG remaining in an LPG cylinder. I'm currently trying out ultrasonic sensor that primarily works as a distance sensor(HCSR04). As far as I'm aware, the lower the frequency higher the penetration of the...
  13. B

    Ultrasound penetration depth?

    Hi, I want to calculate the penetration depth of some different frequency ultrasound transducers. I know that it depends on the attenuation of the medium but not sure where these types of figures will be hiding. I assume that once the dB lost for the depth is equal to the dB generated, this is...
  14. A

    Designing a variable-frequency ultrasonic wave generator

    Hello everyone! Seeing as this is my first post, I'll give you a basic background of who I am: My name is Andrew Raisbeck; I graduated from university with a Bachelor of Computing (Computer Science) degree a little over a year ago, and I now work full-time for the government of Canada. Since I...
  15. Tony Giaccone

    Measuring density with ultrasonics

    I'm interested in determining the density of a dough. I want to be able to continuously measure the density of the dough as it rises. My thought was to use an ultrasonic wave and measure the time it takes to reflect through the dough I would assume that as the dough ferments and the amount of...
  16. R

    Ultrasound NDT (non-destructive testing)

    Hi all, I've a question and I hope that I can get some answers here. As what my project has tasked, and what my lecturer had said. He needs me to build a device for NDT Testing. Currently the set up is that I would source for a transducer via olympus coupled with a USB oscilloscope capable...
  17. X

    FDTD of (ultrasound) wave propagation through muscle

    Im a mechanical engineering student currently, with a third year project of simulating ultrasound propagation through the abdomen. Currently i just want to simulate it going through muscle with no obstacles. I don't really understand where to start, I have formed some equations based on the wave...