Pupils can investigate how sounds can be insulated with this Year 4 Which Material Makes the Best Sound Insulator? PowerPoint. There are pre and post-assessment questions to review understanding, engaging new learning as well as an investigation using a decibel meter to find out which types of material prevent sound travelling due to it being absorbed. This resource also looks at echolocation and how it is used by animals such as dolphins, beluga whales and bats. Download now!