Year 4’s science topic this half term is all about sound and how we hear things. Sound is a very difficult concept for children as we cannot see it. To visualise how a sound wave is made and how sound travels, we conducted two tests and used practical equipment. 

The first involved tuning forks and a bowl of water to show the children how a sound source (tuning fork) vibrates and knocks particles (for sounds, air particles but for this test, water particles). These particles then bash into each other to make a Mexican wave. The wave or ripple made in the water from the vibrations is just the same as the wave of vibrating particles in the air when a sound wave is made and caried.

We then went outside onto the playground in small groups with a drum, a beater and a tub of rice. We sprinkled rice onto the tight drum skin, then tested the relationship between the strength of beat and the vibration on the drum skin and what happens to the rice. The children quickly established that the sound source (drum skin) vibrates more with a harder beat which sends the nearby particles (rice) off quicker and further. This is just like sound being made from a sound source – the larger the vibration the louder and further the noise will travel.