Echoes occur when sound bounces back from a surface which is some distance away
EXAMPLE QUESTIONS
When have you heard an echo?
Why do you think echoes happen?
What makes echoes happen in some places and not others?
SOUNDS TRAVEL OUTWARDS
Sound vibrations travel in all direction away from the source of the sound in a manner similar to the ripples of water created when a stone is thrown into a pond.
Sounds however, travel in all directions, not just outwards, but upwards and downwards as well.
SOUND CAN BE REFLECTED FROM SOME SURFACES
Sound travels much more slowly than light.
We experience this when we see lightning long before we hear the sound of the thunder clap which actually happens at the same time.
Sounds can be reflected from a solid surface and produce an echo (similar to light reflected by a mirror).
We hear many sounds because of reflections.
Echoes occur only when they bounce back from a surface that is some distance away.
You may hear echoes when you are in a cave or a large hall.
