PHYSICS CAMBRIDGE VIII

1. 8.7 THE DANGERS OF SOUNDS
SIR.MUHAMMAD

2. VIII CAMBRIDGE - PHYSICS
Many parts of our ears are very
small and delicate. They can be
damaged by sudden , extremely
loud noises

3. MEASURING THE LOUDNESS OF SOUNDS
THE AFFECTING FACTORS
ON LOUDNESS
THE MEASURING
TOOL
THE MEASURING
UNIT
1- AMPLITUDE
2- DISTANCE FROM THE
SOURCE
A SOUND METER Decibel (dB)

4. THE LOUDNESS OF SOME SAMPLE SOUNDS
Noise Source dB
Breathing 10
A library or quiet classroom 40
Quiet talking 60
Dishwasher 80
Jackhammer 100
Chainsaw 120
Jet taking off 25 metres away 150

5. PROTECTING EARS FROM DAMAGE
The Ear Protectors :
o insulate your ears from sound
o absorb or reflect the sound energy before reaching
the eardrum

6. QUESTIONS
8.7-THE DANGERS
OF SOUNDS

7. QUESTION 1
WHICH PART OF YOUR EAR IS MOST LIKELY
TO BE DAMAGED BY :
a) Exposure to loud noises over a long period ?
b) An extremely loud sudden noise ?

8. QUESTION 2
COPY AND COMPLETE :
a) The loudness of a sound wave is measured in …………….
b) The loudness of a sound ……………. as the distance to the
source increases
c) The loudness of a sound …………….. As the amplitude
increases

9. THANK YOU
SIR.MUHAMMAD