Book 14, Question 107
What Is Ultrasound, and How Do Bats and Doctors Use It?
Ultrasound is sound with a pitch so high that people cannot hear it! The waves are still real, and they travel through air, water, and the body. Bats, dolphins, doctors, and many machines all use ultrasound.
More fun facts
- Any sound higher than 20,000 hertz, too high for people to hear, is called ultrasound.
- Bats and dolphins can hear sounds as high as 100,000 hertz.
- Bats, dolphins, submarines and even some birds use ultrasound echoes, called sonar.
- The echoes tell them how far away and how big something is, which helps them find their way and catch prey.
- Doctors use ultrasound to check inside the body without pain or cutting.
- An ultrasound machine sends out short beeps and times the echoes, since a longer wait means a deeper reflector.
- A computer turns the echoes into a picture of the shapes inside the body.
Sources: openstax.org, openstax.org
Questions kids ask
What else is ultrasound used for?
Its uses range from burglar alarms to cleaning delicate objects.