This week, Year 4 investigated how sound travels – by making their very own string telephones! The classroom was filled with excitement as everyone worked together to design, build and test their creations using cups and string.

The children carefully followed instructions to create their telephones using two cups and a piece of string. Once built, they took turns speaking and listening, testing how well sound travelled from one cup to the other.

We did we find out?

Through our investigation, the children made some fantastic observations:

🔊 Sound travelled better with the string phone
We noticed that voices sounded much louder and clearer through the string telephone than through the air. This helped us understand that sound moves more easily through a solid material like string.

🎯 A tight string works best
When the string was pulled tight, the sound was strong and easy to hear. When the string was loose, the sound became quieter and muffled. We learned that this happens because a loose string absorbs more of the sound, making it harder for the vibrations to travel.

📏 Shorter strings were clearer
We also experimented with different string lengths. The children found that the longer the string, the quieter the sound became. This is because the sound had further to travel and lost some of its energy before reaching the listener.

The children used their knowledge of vibrations to explain what was happening. When we speak into the cup, our voices create vibrations. These vibrations travel along the string to the other cup, where they are heard as sound.