# The Five Senses - Lesson 3: Hearing Activity - Sound is Vibration

Objective
Students can say that sounds are caused by vibrations in things.

Materials
Different-size bottles; same-size bottles; water; wooden spoon or stick; seven-eight glasses that are the same shape and size.

Procedures
The teacher demonstrates that the vibration of air in a container causes sound.

1. Fill bottles of different sizes and bottles of the same size with the same and with different amounts of water.
2. Students predict what will happen if they blow across the tops of the bottles. The students then go ahead and blow on the bottles, trying to see if there is a pattern among the different sounds the bottles make.
3. The students try to sequence the sounds from lowest to highest.
4. If the students are interested, they can make a water marimba. Fill several same-size drinking glasses with water at different levels and strike lightly with a wooden spoon or stick.
5. Students discuss high and low tones in relation to the amount of water in the identical containers.
Getting the Idea
1. What was vibrating that was causing the bottles to make different sounds? (The air inside the bottle.)
2. Did all the bottles have the same amount of air in them? (No, the ones that had a lot of water had only a little bit of air at the top.)
3. When you were hitting the glasses in the water marimba, what was vibrating? (The glasses and the air were vibrating. That is why all the glasses have to be the same shape and height, otherwise the sounds would be different.)