Making and hearing sounds.pptx

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Chapter 8 - Sound and the ear

Par 8.1 - Making and hearing sounds

This chapter

8.1 Making and hearing sounds

8.2 Pitch and frequency

8.3 Sound levels

Crit B test

Crit A + C test on sight and hearing in test week

Bring with you every lesson:

• NOVA Textbook B

• Notebook

• Charged laptop

• Pen

• Grey pencil

• Set square (geodriehoek)

• Calculator

How can we hear things?

• How can things make a sounds?

• How does the sound from a sound source spreads until it reaches my ears?

• How do our vocal cords work when you talk?

What is sound?

Vibrations that travel through the air or another medium and can be heard when they reach a person's ear.

What is sound?

Vibrations that travel through the air or another medium and can be heard when they reach a person's ear.

How can things make a sounds?

Look at the speaker and discuss with your neighbor what you see

How can the speaker make a sound?

Look at the speaker and pick an answer

A

it needs to vibrate the air

B

it needs electricity to vibrate

C

it needs electricity

D

it needs to vibrate

page 181

What if?

These boys have to cross the bridge…

What can they do to make sure that there isn’t a train coming from around the corner?

They can put their ear on the metal tracks to hear the sound of the approaching train

Speed of sound

Sound travels faster when molecules are closer together and slower when they are further apart

Gas → Slow

Liquids → Faster

Solids → Fastest

page 182

How do your make sound?

The vocal cords of Steven Tyler from the band Aerosmith

Watch the video and answer the questions:

What happens to the vocal cords when he is making a low sound?

And when he is singing high notes?

Incredible Human Machine - National Geographic

Individual work time

For next lesson:

• Read 8.1 (page 180-183)

• Answer questions 1, 2, 4, 5, 6 (page 184-187)

After this lesson

• You can give a number of examples of sound sources.

• You can explain how the sound from a sound source spreads until it reaches your ears.

• You can explain how your vocal cords work when you talk