Post on 10-Feb-2022
When hearing is painful Can we damage our ears?
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What is the link?
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What is the link?
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Have you ever wondered…
…what we learned from dolphins and use in submarines today?
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Objectives:
• To describe what noise is and how it can be measured
• Explain some different types of hearing loss
Key words
• decibel – The unit for measuring the loudness of sound (dB)
• Noise – unpleasant sound
• Noise pollution – constant unpleasant sound
• Threshold of hearing – The quietest sound that can be heard
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Temporary hearing loss may be caused by ear infections and colds, after which hearing recovers.
Permanent hearing loss and deafness can be present at birth or occur if the ear is damaged or diseased.
Does everyone have the same hearing range?
Hearing Ranges and Hearing Loss
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Hearing range can be tested using a pitch sweep, in which
the frequency of a sound wave is gradually increased.
This can be created using a signal generator and loudspeaker.
What range of frequencies can you hear?
What is the hearing range of a healthy young person?
Humans can only hear sounds of certain frequencies.
The range of frequencies a person can hear is called
their hearing range.
20 Hz to 20,000 Hz © cgrahamphysics.com 2016
100,000
10,000
1,000
100
10
1
0
human dog elephant bat mouse dolphin
•Which animals hear the lowest and the highest frequencies?
•Which animal has the largest hearing range?
frequency
(Hz)
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The decibel scale
O dB is silence
130 dB is the
loudest you can hear
without pain
Above 140 dB you
get permanent ear
damage
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160
140
120
100
80
60
40
20
0
permanent
ear damage
can just
be heard
aircraft
overhead
decibels
circular saw
at 2m
quiet
countryside
pin being
dropped
loud
bell
personal stereo
The Decibel Scale
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Noise Noise is any unwanted sound louder than 85-90
decibels. Which of these are noisy?
Yes
Yes
Yes
Yes
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Have you ever wondered… Dolphins use ultrasound to find their way.
They use sound to “see”.
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What is the submarine doing?
Why does it need to do this?
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The ear drum…
What will sounds with a high frequency do to the ear drum?
Make it vibrate very quickly
What will sounds with a large amplitude do to the ear drum?
Make it vibrate a larger distance
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Hearing problems
Hearing problems are mainly:
Burst ear drums Wax Broken ossicles
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Ear gets blocked by wax
Accidents or loud bangs can damage the eardrum
Middle ear can get infected
Older peoples bones may fuse
Nerve cells in the cochlea degrade with time
Loud noise may damage the cochlea
This can be treated with antibiotics
This might repair itself
This prevents vibration
There is no cure for this
Signals are not sent to the brain
A doctor can wash this out
How might our ears become damaged?
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Label the parts of the ear BF ear drum has torn
EG middle ear bones have been damaged
DG Never has been damaged
CF ear canal is blocked
AG hairs in cochlea are damaged © cgrahamphysics.com 2016
Ordering volumes
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The units for measuring the loudness of a sound are ________ . We cannot hear any sounds quieter than ________ dB.
When leaves rustle, they have a loudness of ________ dB. People usually talk with a loudness of ________ dB.
Loud noises can ________ our ears and make us deaf. A very loud noise can break the ________.
The cochlea can also be damaged by ________ noise. There are laws to protect people who work in noisy
________. The loudest sound allowed is 90 dB. This is the same loudness as a ________ ________.
________ ________ and explosions are louder than this.
decibel
zero
20
40
damage
Ear drum
loud
places
Road drill
Sirens, thunder
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Reducing noise
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Understanding Checkpoint:
1) If your eardrum breaks you will be deaf forever 2) People use their ears in the same way bats do 3) Antibiotics can treat some hearing problems 4) The ear bones are in the middle of the ear
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Homework, Write a leaflet or design a poster to: • Encourage clubbers to wear ear plugs to
stop damage to their hearing
OR
• Inform patients in a Doctor’s surgery about hearing damage and some advice. Think about what type of people or jobs you might need to consider.
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