6.1 Loudness and pitch of sound

• Physics
• Secondary Education
• Age 12,13

22 March 2023

Unit 6.1 Loudness and Pitch of a Sound

Content objectives

• Describe what is meant by the amplitude of a sound
• Explain how the loudness of a sound depends on the amplitude of the sound wave
• Describe what is meant by the frequency of a sound wave
• Explain how the pitch of a sound depends on the frequency of the sound wave
• Recognise the changes in amplitude and frequency from a graph of the wave or an oscilloscope display

Would you hear a sound in outer space?

Key Question

Which of these is common to all objects that make a sound?

1. They all have particles.
2. They are all in a vacuum.
3. They have particles that are compact.
4. They all carry light.

Sound is made when objects vibrate. 

I agree.

I disagree.

Definition: Loudness

- a way to describe how quiet or loud a sound appears

Can you hear this?

• how much the object is vibrating

Loudness depends on...

• how far away the vibrating object is

Loudness depends on...

The movement of particles in the air is difficult to draw in a sound wave, but it is easier to draw in a graph.

I agree.

I disagree.

• shape of the graph of a sound

Waveform 

• shape of the graph of a sound

Waveform 

peak

trough

phet.colorado.edu

Which waveform shows a louder sound?

Which of the following is the name given to the equipment shown?

1. photometre
2. sound metre
3. oscilloscope
4. caleidoscope

What do you see in an oscilloscope?

22 March 2023

Unit 6.1 Loudness and Pitch of a Sound

Which of these lengths of ruler causes a higher pitch of sound?

20 cm

10 cm

Definition: Frequency

- the number of vibrations in each second (or per second)

phet.colorado.edu

Which waveform shows a higher pitch?

Group Task

• Gather together as a team.
• Accomplish the given tasks.
• Present your output.

Plenary (Sharing)

What's next?

End of Unit 3 Assessment