Dangerous Sound Lesson aims To learn how sound can be dangerous and what can be done to reduce the...
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Transcript of Dangerous Sound Lesson aims To learn how sound can be dangerous and what can be done to reduce the...
Dangerous Sound
Lesson aims
To learn how sound can be dangerous and what can be done to reduce the risks of hearing damage
Learning outcomes
By the end of the lesson you should • State that loud sounds can damage
hearing• Compare sound levels using the
decibel scale• Describe how hearing can be
impaired using ear model• Describe how to reduce noise
pollution
How are loud sounds made?
• How can the loudness of a sound be measured?
• Why are very loud sounds dangerous?
• What is the easiest way to quieten sounds?
We can use a sound level meter to measures sounds
Sound levels
Sound : How loud are sounds?
150
140
120
100
80
60
40
20
10
0
Permanent ear damage
Can just be heard
Aircraft overhead Personal stereo
A circular saw at 2m
Loud bell
Pin being dropped
Quiet countryside
dB
Can damage
Hearing
Explaining noiseStudy this picture and read the comments
Read pages 105-106
What is noise?
A noise is any unwanted sound. What you might not consider noise, loud music for example, other people might.
What are the effects of noise?
1. _________
2. _________
3. _________
4. _________Nausea
Vomiting
Headaches
Deafness
How can you reduce the effects of loud noise?
1. _________________
2. _________________
3. __________________________________
Ear protectors
Putting noisy machinery in insulated rooms
Double glazing
What is noise pollution?
How can noise pollution be reduced? Explain how soft materials quieten
sounds
What is the upper range of human hearing?
A. 20 Hz
B. 200 Hz
C. 2 000 Hz
D. 20 000 Hz
Measuring sound
How does this compare to the graph for our lesson?
Research the reasons for damaged hearing
• www.evelyn.co.uk• http://www.hse.gov.uk/noise/index.htm
• Pages 107 Spectrum
• Homework: research the factors that affect the speed of sound explain these in a poster