ultrasound

Everyday

1. Ultrasound is sound that is too high-pitched for humans to hear, but some animals like bats and dogs can hear it. tree →
2. An ultrasound (scan) is a medical test that uses these sound waves to make a picture of the inside of the body, often used to look at a baby before it is born. tree →
3. Ultrasound is also used in cleaning machines and in some medical treatments. tree →

In the lessons

In science lessons ultrasound shows that sound is a vibration and that some sounds are beyond our hearing range; bats and dolphins use echoes of high sounds to find their way (echolocation). In everyday family life, a parent might show a grainy ultrasound picture of a new baby. It is safe and does not use X-rays. Phrases: «ultrasound scan», «have an ultrasound», «ultrasound picture».

Examples

• Mum showed us the ultrasound of our baby sister. tree →
• Bats use ultrasound to find insects in the dark. tree →
• The doctor used ultrasound to look at Dad's sore knee. tree →
• We can't hear ultrasound, but a dog whistle shows dogs can. tree →
• The ultrasound picture looked like a fuzzy black-and-white blob. tree →
• Dolphins send out ultrasound clicks and listen for the echoes. tree →
• Ultrasound waves bounce back from things inside the body. tree →

Note

Uncountable for the sound itself; countable for a scan (an ultrasound, two ultrasounds). «Ultra-» means beyond: beyond the sounds we hear. Compare «infrasound», which is too low to hear. An ultrasound is not an X-ray.