ultrasound

American  

[uhl-truh-sound] / 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

Etymology

Origin of ultrasound

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

Compare meaning

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

• ultrasonic vs. ultrasound

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

It contains testing kits for tuberculosis, cooled storage for vaccines, and ultrasound for pregnant women.

From Barron's ● Jul. 21, 2026

Dutch peer Royal Philips doesn’t compete in radio-oncology or positron emission tomography, but it is already seeing pressure through centralized procurement of ultrasound equipment, the analysts say.

From The Wall Street Journal ● Jul. 15, 2026

"Our team is interested in continuous low-intensity ultrasound because it offers a non-pharmacological, non-invasive approach that may help regulate immune cell behavior and promote a more reparative healing environment in injured joints."

From Science Daily ● Jul. 12, 2026

The researchers found that continuous low-intensity ultrasound lowered biological markers linked to inflammation while increasing markers associated with a more reparative, M2-like macrophage state.

From Science Daily ● Jul. 12, 2026

Before the ultrasound she had asked the doctor not to tell her the sex of their child, and Shukumar had agreed.

From "Interpreter of Maladies" by Jhumpa Lahiri

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

From Los Angeles Times ● Jul. 18, 2026

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

From Slate ● May 10, 2026

On her third visit, as Crain’s condition deteriorated, a doctor did not send Crain to the intensive care unit until he could confirm fetal demise with two ultrasounds.

From Salon ● Apr. 20, 2026

The vet is worried about the new policy: "We will have meetings every month, where one of the area teams will ask you how many blood tests, X-rays and ultrasounds you're doing."

From BBC ● Jan. 12, 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