When hearing is painful Can we damage our ears?
What is the link?
What is the link?
Have you ever wondered what we learned from dolphins and use in submarines today?
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
Hearing Ranges and Hearing Loss Does everyone have the same hearing range? 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.
What range of frequencies can you hear? Humans can only hear sounds of certain frequencies. The range of frequencies a person can hear is called their hearing range. 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 is the hearing range of a healthy young person? 20 Hz to 20,000 Hz
Which animals hear the lowest and the highest frequencies? Which animal has the largest hearing range? 100,000 10,000 frequency (Hz) 1,000 100 10 1 0 human dog bat elephant mouse dolphin
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
The Decibel Scale aircraft overhead quiet countryside pin being dropped decibels 160 140 120 100 80 60 40 20 0 permanent ear damage personal stereo loud bell circular saw at 2m can just be heard
Noise Noise is any unwanted sound louder than 85-90 decibels. Which of these are noisy? Yes Yes Yes Yes
Have you ever wondered Dolphins use ultrasound to find their way. They use sound to see.
What is the submarine doing? Why does it need to do this?
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
Hearing problems Hearing problems are mainly: Burst ear drums Wax Broken ossicles
How might our ears become damaged? 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 cgrahamphysics.com may damage 2016 the cochlea This can be treated with antibiotics A doctor can wash this out This might repair itself This prevents vibration There is no cure for this Signals are not sent to the brain
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
Ordering volumes
The units for measuring the loudness of a sound are decibel. We cannot hear any sounds quieter than zero db. 20 When leaves rustle, they have a loudness of db. People usually talk with a loudness of 40 db. damage Loud noises can our ears and make us deaf. A very Ear drum loud noise can break the. loud The cochlea can also be damaged by noise. There are laws to protect people who work in noisy. places The loudest sound allowed is 90 db. This is the same loudness as a Road. drill Sirens, thunder and explosions are louder than this.
Reducing noise
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
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.