Today, with 3rd Grade pupils, we have made an EAR DRUM model (we are learning about the sense of hearing).
The EAR DRUM is a very sensitive organ, inside our ears, which vibrates when sounds pass through it.
With very common materials (a can, a balloon and salt), we built a model of it. To see how it works, you just have to make loud sounds near it and then observe how the salt moves without touching it, just by the vibration of the balloon (=ear drum):
