It is possible to see an alarm clock ring as well as to hear it. When you are standing close to the alarm clock, it seems quite loud. As you move away from the clock, the alarm sounds quieter, so our distance from the source of a sound will affect how loud it seems.

First broadcast:
15 October 2007

After watching the clip, ask pupils to close their eyes. What sounds can they hear? List the pupils' responses. Ask: "Which sounds are near to you and which sounds are far away?" Give one child a drum and have them beat it outside the classroom, at some distance away and then to come gradually closer. Can the other children decide when the drummer is right outside the door? The children could be asked to sit in a circle with one child blindfolded at its centre. Pass a small bell around the circle. When it rings, the child at the centre can try to point at the child holding it. Ask: "How good are our guesses? Is it easier to hear when the bell is in front of us?" Let everybody have a go with the blindfold.