intro:
Children may be somewhat familiar with echoes, but this activity will give them an opportunity to really hear them and note their unique qualities, as well as learn what sorts of materials and structures are effective at producing echoes.

set up ideas:
To create interesting acoustic echoes, you'll need an object that will ring out such as a small tin can or a metal bucket. Be careful with sharp edges and cover them with duct tape if needed.

let's get started

 
You'll need to gather objects such as washers, blocks, coins, rocks, etc. You also may wish to use a sheet of art foam cut to the size of the inside of the can to hear how it affects the sound.

 
step 1
Invite the children to first speak into the can and listen for the echo of their voices. Be sure to cover any sharp edges with duct tape.
step 2
Drop the items gathered into the can, one at a time. Listen closely to hear the echoes as the items land in the bottom of the can.
step 3
Repeat each item as needed or desired and have the children suggest other items to drop into the can.
step 4
Discuss how the echoes vary from one material to the next. Which items seemed to echo the loudest? Which echoed the least?

Conversation
This is a great activity to get children thinking and talking about sound. How is the sound of dropping an item in the metal can different from dropping it on the floor or on a table? Where else have children heard echoes?
Tips and Tricks Tips and Tricks
Before demonstrating the sound of echoing inside the can, try dropping item onto a table, floor or another surface. This will help children compare the sounds created in different environments.
Follow Up ActivityFollow up Activity
Vary this activity by first placing the foam piece around the edge. Have the children drop the items one at a time. What has changed with the sound?