Echolocation and SONAR: Indoor Unit

Students explore the idea of how it feels to use sound to locate objects.

Grade Level

1-12

Clean-Up

10-15 minutes

Learning Goals

Students will be able to:

• Define SONAR and Echolocation and give examples of several animals that use these tools.
• Explain the difference between locating food that is on the ground versus all around such as up in the air or if we were swimming above, below and side to side.

Materials not in Kit

A second room or space
Blindfolds – 1 per group
Rulers – 1 per group
Cotton balls
Pencils, dry erase markers, crayons, etc.
About 15 buttons of different shapes, sizes & colors
String
Tape
Laser pointers or narrow beamed flashlight*
Additional adult supervision**

*Check the packaging to make sure the laser pointer is safe for kids. Laser pointers work better than a flashlight, but a flashlight can be substituted if necessary. The narrower the beam of light, the better.

**An additional adult supervision may be useful for the 3D Location section, particularly if the students need to go to another room in the building.

 

Set-Up

1. Attach string to buttons. Make the strings a range of lengths.
2. Clear out the second room room or space so that there are no obstructions on the floor.
3. Hang the buttons from the ceiling at different places.
4. Turn of the lights and close curtains to darken the room as much as possible.
5. Place a piece of tape or rope across the doorway so students can’t enter the room.

Introduce the Activity

First, students will turn in their homework assignments from the night before.

Explain that in the following lesson there will be two activities. One will be using sound rather than sight, and the other students will use a laser pointer to find objects around a dark room. Introduce both activities so students are aware of what they are doing.

While all students are working on the Using Sound Rather than Sight sections, small groups of students will be going into a dark room to complete the 3D Location activity.

 

Doing the Activity

Using Sound rather than Sight

1. Divide the students into groups of 3-5. One student will wear the blindfold.NOTE: We put cotton balls under the blindfold on the eyes so students can’t peek under the blindfold.
2. Have another student in the group drop an object on the floor. The blindfolded student has to guess:
   

   → What object fell
   → Where they think the object fell.

   NOTE: They should place their hand down directly to guess where the object fell- no fishing!

3. Students should try dropping the objects at different locations around the room, including behind the blindfolded person and between their feet.
4. Students should do this five times each, so that everyone has a chance to be a dropper and as a blindfolded guesser.
5. As the blindfolded student makes guesses, the student in charge of dropping the objects should fill out the chart from the worksheet.
6. After everyone in the group has had a turn being blindfolded, have them answer questions 1-6 in their packets.

3D Location

1. Explain that animals use echolocation in the water and in the air. Ask the class to come up with animals that use echolocation.
   

   Ex. bats and dolphins

2. Explain that in our world, we are typically only concerned with 2 dimensions, but echolocators have to look up, down, left and right, so they are dealing with 3 dimensions.
3. One group of 3-5 students will enter the dark room for 10 minutes.
4. Using the laser pointer, students should identify as many buttons as possible. They should describe the size, shape, and color and location.
   

   NOTE: Students should look for the buttons directly, not the string attaching them to the ceiling! Bats and dolphins don’t have strings to use when searching for food.

5. After all the students have done the activity, discuss the following topics:
   

   a. Animals that use echolocation are able to send out very narrowly focused sound so that they can easily pinpoint the location of objects and fish. Why do you think you used a laser pointer instead of a flashlight?

   b. Verbally list the size and location (in all 3 dimensions) of every button identified with the laser pointer.

Explanation

People have a harder time locating objects right between their feet or directly in front or behind them. Our brains are able to detect the time delay for sound arriving at each ear. Using this delay our brain determines to which side the object fell and how far away it is. When an object is right between our feet or directly in front or behind, the sound arrives to each ear at the same time.

 

Key Lesson Terminology

Echolocation – A method used to detect objects by producing a specific sound and listening for its echo.

SONAR – Sound Navigation And Ranging, is the process of listening to specific sounds to determine where objects are located.

Echolocation – A method used to detect objects by producing a specific sound and listening for its echo.

 

Optional Extensions

In the 3D location activity, students can try using a flashlight after they have used the laser pointer to see if the activity is easier or harder.