Investigating String Telephones

This week I asked the senior classes whether they thought sound could travel through things apart from air.

They thought sound could travel through water and solid things.
This is correct.

The next challenge was to test how well sound travels through a string telephone. String telephones work because when a person talks into the cup the sound waves travel along the string to the person at the other end.
There were 12 different types of string telephones to test. The aim was to find out which type of cup and which type of string allowed the sound waves to travel the best.

4 types of cups - plastic, paper, polystyrene, tin can
3 types of string - wool, cotton, plastic

Before students began they had to predict which combination would work the best. Most people thought the tin can and plastic string telephone would work the best.

However, after testing the different types of string telephones they found out that the plastic cup with the cotton string worked the best because you could easily hear the words.
Students then had to come up with a theory as to why this combination of string and cup allowed the sound vibrations to travel the best.