Making an Eardrum Model
You might need the help of a grown-up or older brother or sister to make this eardrum model. They're sure to help. Just tell them that science with kids is loads of fun!
Materials
1 plastic bowl/ round container with a wide opening (old cookie jars do pretty well too)
a few grains of uncooked rice/ a few small seeds
plastic covering/ a plastic sheet (try the one often used to wrap textbooks, but make sure it's thin plastic)
scotch tape
a large metal sheet (metal baking trays are usually the best)
1 stick, either plastic, metal or wood
Instructions
Make sure your plastic bowl/ container has nothing inside it.
Cover the bowl or container with the plastic covering or plastic sheet and attach the ends of the plastic sheet to the side of the bowl or container with scotch tape. Make sure the plastic covering is tight over the opening of the bowl or container.
Place the grains of uncooked rice or small seeds on top of the plastic covering.
Take the metal sheet and hold it right beside the bowl.
Bang on the metal sheet with the stick. You should notice that the seeds or rice will have jumped.
Bring the sheet further away from the bowl, and bang on it again. You will see that the seeds or rice jumped, but not as high.
Concept Explanation
The bowl with tight plastic covering over it is an example of the ear drum. The rice or seeds show us how the eardrum vibrates when it receives sound waves through the air. We all have tiny hairs in our ears, and these also move with sound vibrations, and they help us hear. In this easy project, science, with kids, shows how sound waves affect the rice, causing it to jump in the same way that sounds affect our eardrums causing it to vibrate. When a sound wave is emitted, our eardrums and tiny hairs vibrate, allowing us to hear sound. If the sound is really close by, the sound is loud and our eardrums vibrate a lot (high jumping rice). If the sound is far away, the sound is not so loud, and our eardrums vibrate less (low jumping rice).
