Script: Welcome back, acousticians! You’ve been learning all about how sound travels via waves. Think about your sense of hearing–how does it impact your life? Wait for student response. Sounds can help us identify things and understand the world around us. A sound might be a warning, a welcome, or just something to enjoy, like music. Today, you’ll continue studying sound as we learn more about how sound can help us learn about our world. Let’s play a quick game to find out what sounds we can recognize through hearing alone.
5 min Play a sound recognition game with students to test out their sense of hearing.
5 min Discuss:
5 min Script: The sounds we can hear are only a fraction of the existing sounds on earth. Different animals can hear sounds at different frequencies than humans. That’s why pets like dogs and cats may perk up at what seems like nothing to us.
Other animals use sound to their advantage when it is difficult to see, or to communicate over long distances. This is called echolocation. Have you heard of echolocation before? What do you think it means? Wait for student response. Animals that use echolocation rely upon the echo of sounds. What is an echo? Wait for student response. An echo is a reflected sound. It occurs when the sound vibration bounces off of a physical surface and travels back to you. Echolocation is the process of identifying the location of objects by reflected sound. What animals do you know of that use echolocation? Wait for student response. Let’s watch a video to learn more!
10 min Watch: What is Echolocation: Earth Unplugged (www.youtube.com/@earthunplugged)
5 min Discuss:
Students experience the concepts of echolocation and SONAR by engaging in a listening activity while blindfolded.
This lesson was modified and adapted from TeachEngineering.org/
5 min Script: We know that the discovery of echolocation used by animals like whales and bats helped people create technology like SONAR. But what is it actually like to rely upon your sense of hearing to help “see” what is around you? In this activity, you’ll experience the concept of sonar/echolocation by engaging in an activity with a partner.
10 min: Demonstrate the Echolocation Activity
20 min Assign partners and dismiss students to engage in the Echolocation Activity
5 min Discuss the Echolocation Activity. Ask the following questions:
5 min Script: People have taken inspiration from animals that use echolocation to design a technology called SONAR. The word SONAR comes from a combination of the phrase “sound navigation and ranging”. Like animals, the technology of sonar allows people to navigate their surroundings using sound waves. Sonar can help people determine the distance, location, and general shape of objects that may otherwise be difficult to see. Sonar sends out sound waves that echo back and allow a computer to create a basic image of the surroundings. Let’s watch a short video to learn more.
5 min Watch: National Ocean Services: What is sonar? (https://oceanservice.noaa.gov/) (NOTE: You can also download the video to play)
5 min Discuss:
10 min Script: Animals that use echolocation rely upon it for their everyday activities. While humans don’t rely on sonar for simple everyday tasks, it is an important technology that has helped to improve the world we live in. Sonar has many different applications—from medical to navigational, and more! Now we’ll take some time to learn more about some of the different ways sonar is used.
First, let’s think about medical applications. Why do doctors and surgeons need to see inside of the human body? To find and diagnose problems. You may be familiar with x-ray machines. X-ray is a common machine that allows you to see the human skeleton, but to see other parts of the human body like organs we use a type of sonar called ultrasound. Let’s watch a short video to learn more:
2:30 min Watch: What is Ultrasound? (https://hartfordhealthcare.org/)
Sonar is also an important military technology. Have you ever seen a submarine? Wait for student response. Submarines are specialized underwater vehicles. A submarine is completely sealed off with no windows to see out of. For that reason, submarines navigate the ocean using sonar. Let’s watch to learn more:
1:30 min Watch: Submarine Sonar (pbskids.org)
Another way sonar is used in navigation is in the exploration of hard to reach places, like caves. Have you ever been in a cave? If so, what was it like? Wait for student response. Caves are underground and are usually very dark. They tend to have lots of nooks, crannies, and tunnels. Cave systems can be very large and we often don’t even notice them when we’re above ground. Let’s find out more about how explorers use sonar and other tools to create maps of cave systems:
6:30 min Watch: Mapping the Labyrinth (education.nationalgeographic.org)
Finally, sonar can be used to help fishermen find fish. Just like sonar is used to find land masses and underwater features, it can be used to find living things just like how bats use echolocation to find insects for food. Fishermen can use sonar systems to help them locate fish, increasing how many fish they are able to catch in a single day. This short video shows us how:
1:30 min Watch: What is Sonar Fish Finding? (https://humminbird.johnsonoutdoors.com/)
5 min Discuss:
Have students select one of the uses of sonar taught in this activity to research. Have students research the sonar use and record their responses to the following prompts:
