Ask a friend (or your mum, dad, etc.) to stand 5 metres away from you. Now whisper something. Can they hear it clearly?
Now whisper through a tube. Have your friend follow the tube and listen at the other end. Can they hear you clearly now?
The first time your friend probably didn’t hear your whisper. The sound of your voice travels in every direction, so it fades quickly. But the second time they could hear you very clearly. That’s because the walls of the tube hold in the sound. The sound bounces back against these walls and therefore follows
the tube. As a result, your whisper can be heard further than it otherwise would.
Sound reflection with echoes
When you call something in a deep cave or a long tube, the sound that you make collides with the rockface or the end of the tube and bounces back to your ear. As a result, you hear an echo.
Would you like to try it out? Go to our Echo tube on the top floor.