Today we did some sound experiments with a balloon. Our question was whether a balloon would make sounds louder or softer. We wrote our predictions on a whiteboard, and then discussed them with a partner.
Some of us thought the sound would be softer, and others of us thought it would be louder. We shared some of our reasons.
Adam: It would be softer, because the balloon is softer.
Emma: It would be so loud, because the balloon would break.
Pieter: It would be louder, because tapping on the balloon would pop it and it would make a very loud boom.
Ms Leah: What if Teddy promises to tap really, really lightly. Would the balloon still pop?
Nora: Not if he was really careful it wouldn't.
Ms Leah: Does that change your theory then?
Emanie: No, it would still be louder.
Johnny: Yes, it would be louder.
Pieter: Not if it didn't pop.
There were many different theories. We decided to test them.
Teddy first tapped the ground. We couldn't hear it. Then he tapped the balloon and we heard a sound!
Adam: It's because the balloon is a different material.
Claire: The balloon is made of rubber.
Emma: The balloon is very soft, but the ground is so hard.
Ms Leah: Okay, lets see if we can find something else soft to test.
Siena: I know, tissue. Tissue is very soft. You can test the tissue.
Frankie tapped the ground. We couldn't hear it. He tapped the tissue. Most of us couldn't hear anything. He then tapped the balloon. All of us heard the sound!
Griff: It's not the material. It's the air. The air inside it. Ms Leah's breath. It makes the sound travel more.
We decided to test out this theory further by playing the telephone game. The first time just whispering quietly, many people had a difficult time hearing. We only made it a bit around the circle and already it was tough and the word had changed.
Then we tried playing the telephone game through a balloon. It was so much easier to hear!