ultrasound

American  

[uhl-truh-saund] / ˈʌl trəˌsaʊnd /

noun

• ultrasounds
  plural

1. Physics. sound with a frequency greater than 20,000 Hz, approximately the upper limit of human hearing.

2. Medicine/Medical. the application of ultrasonic waves to therapy or diagnostics, as in deep-heat treatment of a joint or imaging of internal structures.

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ultrasound British  

/ ˈʌltrəˌsaʊnd /

noun

1. ultrasonic waves at frequencies above the audible range (above about 20 kHz), used in cleaning metallic parts, echo sounding, medical diagnosis and therapy, etc

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ultrasound Scientific  

/ ŭl′trə-sound′ /

1. Sound whose frequency is above the upper limit of the range of human hearing (approximately 20 kilohertz).

2. See ultrasonography

3. An image produced by ultrasonography.

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ultrasound Cultural  

1. A method of diagnosing illness and viewing internal body structures in which sound waves of high frequency are bounced off internal organs and tissues from outside the body. The technique measures different amounts of resistance the body parts offer to the sound waves, and then uses the data to produce a “picture” of the structures. Ultrasound is often used to obtain an image of the developing fetus in pregnant women; the image can confirm the presence of twins or triplets and can be used to diagnose some abnormalities.

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Closer Look

Many people use simple ultrasound generators. Dog whistles, for example, produce tones that dogs can hear but that are too high to be heard by humans. Sound whose frequency is higher than the upper end of the normal range of human hearing (higher than about 20,000 hertz) is called ultrasound. (Sound at frequencies too low to be audible—about 20 hertz or lower—is called infrasound.) Medical ultrasound images, such as those of a fetus in the womb, are made by directing ultrasonic waves into the body, where they bounce off internal organs and other objects and are reflected back to a detector. Ultrasound imaging, also known as ultrasonography, is particularly useful in conditions such as pregnancy, when x-rays can be harmful. Because ultrasonic waves have very short wavelengths, they interact with very small objects and thus provide images with high resolution. For this reason ultrasound is also used in some microscopes. Ultrasound can also be used to focus large amounts of energy into very small spaces by aiming multiple ultrasonic beams in such a way that the waves are in phase at one precise location, making it possible, for example, to break up kidney stones without surgical incision and without disturbing surrounding tissue. Ultrasound's industrial uses include measuring thicknesses of materials, testing for structural defects, welding, and aquatic sonar.

Discover More

When an image of the inside of the body is needed, ultrasound is often considered a safer alternative to x-rays. Like x-rays, ultrasound involves exposure of the body to a form of radiation; unlike x-rays, ultrasound has not been shown to be carcinogenic.

Other Word Forms

Noun Inflected Forms

• ultrasounds
  plural

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Etymology

Origin of ultrasound

First recorded in 1920–25; ultra- + sound ¹

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Compare meaning

How does ultrasound compare to similar and commonly confused words? Explore the most common comparisons:

• ultrasonic vs. ultrasound

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Explanation

The noun ultrasound is a medical term for a scan that allows doctors to easily and safely see inside a patient's body. An ultrasound uses inaudible sound waves to create a picture of a person's internal organs, muscles, bones, and other body parts. The type of ultrasound that's most familiar to non-medical professionals is the kind that allows a doctor or technician to see a fetus from the outside of a pregnant woman's stomach. The person who performs an ultrasound is called a sonographer or a radiologist.

Example Sentences

See Examples For:

ultrasound ultrasounds

The mum-of-two, from Merthyr Tydfil, first noticed a "small pea-sized" lump in her breast in 2018, but, after an ultrasound, she was told it was likely glandular tissue and no biopsy was carried out.

From BBC ● Nov. 2, 2026

To deliver these molecules into the brain, the researchers combined specialized nanoparticles, focused ultrasound and microscopic bubbles.

From Science Daily ● Nov. 1, 2026

A follow-up ultrasound was recommended within 72 hours and Hurts was cleared for the flight home.

From BBC ● Oct. 28, 2026

They also performed ultrasound examinations to measure the size of the median nerve, an indicator of swelling.

From Science Daily ● Oct. 22, 2026

She and my stepmom were comparing ultrasound photos of their fetuses at dinner.

From "Simon vs. the Homo Sapiens Agenda" by Becky Albertalli

The content creator said her daughter underwent numerous X-rays, ultrasounds and a biopsy before the hospital team determined the cancer diagnosis.

From Los Angeles Times ● Jul. 2, 2026

The policy covered her IVF procedures, ultrasounds and lab work after she met the deductible.

From The Wall Street Journal ● Jun. 7, 2026

Doctors and nurses with Doppler machines and ultrasounds kept showing up, forcing them to hear the heartbeat and see the movement of a tiny body.

From Salon ● May 27, 2026

In exchange for crumbs of egg, wild meerkats will climb onto scales and even hold still for ultrasounds.

From Slate ● May 10, 2026

In the weeks to come, he’d go about his regular business while I went in for daily ultrasounds to monitor my eggs.

From "Becoming" by Michelle Obama

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