This experiment involves making a model of the ear so that you can see how it changes sounds into signals that are sent to the brain. You will need a piece of card, sticky tape, plasticine or Blutac, a rubber band, a torch, a cardboard tube, clingfilm and a sheet of paper.
1) Stretch the clingfilm over one end of the tube and secure it with a rubberband.
2) Roll the sheet of paper into a cone and fasten it with sellotape. Stick it in the other end of the tube.
3) Stand the card upright on a table and secure it with Blutac. Now shine the torch onto the clingfilm so that a spot of light appears on the card.
4) Now shout or sing very loudly into the cone. The spot of light will shake.
The sound waves that you send out make the clingfilm wobble. The wrap is like your ear drum. The cone acts like the outer ear which channels sound into the ear canal (the tube). The cardboard tube is like the ear canal.
