We hear sounds when objects vibrate. The vibrations make the air around the object vibrate and it is these vibrations that enter our ears to be heard as sounds.
The loudness of a sound is how loud or soft it is. If you hit a drum hard it makes a very loud sound, if you hit it gently it makes a soft sound.
Sound vibrations can travel through air, water and solid materials, but travel through some materials better than others. This investigation allows children to discover whether some materials are better than others at muffling sound.
- A cardboard tube
- Materials to test: bubble wrap, kitchen towel, anything else you think might muffle sound.
- Understand how sounds are made and associate them with something vibrating.
- Understand that some materials absorb/muffle sound better than others.
- Recognise that vibrations from sounds travel through air\water etc to get to the ear.
- For this activity you need a speaker and listener. The speaker first places the cardboard tube to the ear of the listener and speaks at normal volume into the tube. The listening person should be able to hear what is said.
- Repeat step 1 after filling the tube completely with one of the test materials and record if the listener can still hear what is said.
- Test each material in the same way. The same person must be the listener and the same the speaker each time and the speaker should speak at their normal volume.
Ask the children to predict which materials will be the best sound absorbers before carrying out the activity.
Try wrapping something that makes a noise in different materials. Remember only one condition should be changed for each type of material and every other variable kept the same. Use the same amount of each material and the same noise maker at the same volume for each test condition.
This is a great activity for getting children to think scientifically by designing the investigation to be a fair test. This means only one variable ( the material used to fill the tube ) should be changed for each condition and everything else kept the same.
Did you know our ears are shaped to catch sound waves?