Recognise that Sound Volume is Related to the Distance from the Source

In this activity, we will be looking at how sound gets fainter the further we are from the source. 

 

First of all, how is a sound created? 

 

    

 

The drums will vibrate and create sound waves. Each wave sound will bump into the closest air particles. 

 

This will make the air particles vibrate and pass the vibration onto the next air particles - this is how the sound passes along. 

 

This picture shows the sound waves leaving the drum, and vibrating the closest air particles which are shown as the blue dots. In real life, air particles are so small we cannot see them! 

 

  

 

 

 

However, the further away from the source of the sound you are, the quieter the sound will be. 

This is because the waves lessen until they don’t have the strength to vibrate any other air particles.

 

This picture shows the sound waves getting smaller and bumping into fewer air particles. 

 

  

 

 

The size of the vibration is called the amplitude - the stronger the vibrations, the louder the sound or the bigger the amplitude.

 

Quiet sounds have smaller vibrations, so they have a smaller amplitude. 

 

When a sound leaves the source, the amplitude is bigger.

The further away from the source we are, the smaller the amplitude. 

 

     

 

Are you ready to have a go at some questions?