S2.7.3 For the adult
Echoes
Why do I hear my shout again from a far wall?
What this chapter teaches
An echo is sound that bounces back from a hard surface, and soft things take sound in. A separate echo needs a wall about 17 metres away or more.
Three questions to ask
There is no one right wording. Listen for the idea.
- Where would you stand to hear an echo, and what would you do?
- Why does a room with cushions and curtains echo less?
- How might a bat use an echo to find an insect in the dark?
After the chapter, the learner can
- Explain that an echo is sound bouncing back from a hard surface
- Say which things bounce sound back and which take it in
- Explain how bats and dolphins use echoes to find food
What they copy into their notebook
An echo is sound that bounces back from a hard surface. Soft things take sound in. Dolphins and many bats send out sounds and listen for echoes. They find food this way.