We've looked at how sound is generated and travels - but how can it be stopped? Have a watch of this short clip which uses Nerf guns to show soundwaves and how a room can be made quieter. Which materials do you think would be best at absorbing or diffusing sound (and what do those words mean? If you've watched the video you'll know!)?
Here's the challenge - if you had to make some earphones to absorb or diffuse sound, which materials do you think would work well? Get practical! You can see if there's anything around your home that you could cover your ears with - which one works best at blocking out sound? Why? Log onto PurpleMash and on your 2Dos you'll find Day 1 - Sound Insulation. Tell me what you find out!