Listen Up! Science - Year 4 Sound – Block 4S Session 5 PowerPoint © Original resource copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users. We refer you to our warning, at the foot of the block overview, about links to other websites.

When is it important to hear the sounds around us?

When should we try to muffle sound from travelling to our ears?

Remember your challenge from the 1st Session? Now that you know so much about sound, I think you’re ready! The Rock Stars of the world need your help!!! They want their children to be able to come to their concerts, but they are worried about their precious hearing. The concerts will be very loud; too loud for such young ears! Learn all you can about sound and hearing then design some ear defenders for the young rockers!

In groups, you will test different materials to discover which is the best at reducing sound. How do you think this could be investigated? Discuss with the people on your table and come up with some ideas. Think

You must ensure that you carry out a fair test. What does this mean? When you present the final product to the famous panel, they will want to know that your results are valid. You must ensure that you carry out a fair test. What does this mean? Fair test? http://resources.hwb.wales.gov.uk/VTC/16022007/sound_travels/lesson.html

A fair test is an investigation where only one factor (variable) is changed while all the others are kept the same (controlled). This way, we know that any changes found are only because of the thing we want to test.

Let’s try to think of some of the variables of our investigation. Which is the only variable that should be changed?

Is it fair?