when a sound is heard more than once because sound waves have reflected back

materials that absorb sound reduce the vibrations of the air (as sound is easily transmitted to/through them)

Reflecting and absorbing sound

Science

Sound vibrations

Travelling vibrations

Travelling sound

Shadows

Reflecting light from mirrors

How we see things

Reflections in mirrors

In the Making images unit, they will build on this knowledge to learn that white light is made of different colours that can be detected by the eye, and how pinhole cameras and lenses form clear images.

In the Light and how it travels (Y6) unit, pupils learnt that light travels in straight lines, which explains why shadows have the same shape as the objects that cast them, and objects are seen by the light that reflects back into the eye or travels directly into it from a light source.

This unit explores sound and light waves, including frequencies, echoes, reflection, absorption, and the need for a medium for sound to travel. It also compares light and matter waves, investigates light transmission and colour, and examines wave properties and effects.

Sound, light and vision

When an object absorbs sound, its particles vibrate more.

Softer materials absorb more energy from sound waves than harder materials.

When a sound wave enters a solid, it travels through gaps between particles.

Which of the following statements are correct?

The energy of the sound has been used up.

The sound wave has been absorbed by walls and other objects.

The sound can now be heard somewhere else instead.

The energy of the sound has transferred to the thermal store.

A person hits a drum in a room. After they stop hitting the drum, they cannot hear the sound any more. 
Which of the following statements explains why this happens?

A person stands 5 metres away from a wall outside and claps. They hear an echo. 
When the person hears the echo, how far has the sound wave travelled?

Which of the following characteristics of a surface allow it to produce clear echoes?

Which of the following is the correct definition of ‘noise’?

In a music recording room, echoes are usually not wanted. 
Which of the following methods are most effective at reducing echoes in the room?

Which of the following words describes a repeated back and forth movement?

Which of the following words is used to describe what all solids, liquids and gases are made of?

Air travels from one side of the room to the other.

Sound particles travel from one side of the room to the other.

Sound passes between the air particles from one side of the room to the other.

A pattern of repeating movements travels from one side of the room to the other.

A drum on one side of a room is hit. It makes a sound that travels to the other side of the room. How does the sound travel across the room?

What is the name of the process when a wave ‘bounces’ off a surface?

What name is given to the process when a wave loses its energy after travelling into a material, so that it neither bounces off nor travels all the way through?

The wave increases the random movements of air particles.

The wave decreases the random movements of air particles.

When a sound wave travels through air, it makes the air heat up a little. 
Which of the following statements explains why this happens?

Reflecting and absorbing sound

Lesson outcome