Speech Bubble

You may have heard of the early hearing aid known as an "ear trumpet" – but here’s another idea, the "ear balloon"!

You will need:

* an inflated balloon (NB If you are under 8 years old please ask an adult to inflate the balloon for you)

* a volunteer


What to do:

1. First, ask your volunteer to stand across the other side of the room.

2. Turn your back on them, and ask him or her to whisper a message to you.

3. Now, position your balloon beside your ear. Hey – you’re lookin’ good!

4. Ask your assistant to whisper a second message at the same volume as before.

Can you hear the message better with the balloon at your ear?


What's going on?

The air in the balloon is under greater pressure than normal air. This means that inside the balloon air molecules are closer together than in normal air, so sound will travel better through the balloon as it will travel more quickly.