1. The Ear
D. Crowley, 2008

2. Thursday, July 18, 2019
The Ear
To be able to label the ear, and to know the function of each part

3. Hearing
How do we hear?
Ears change sound energy into electrical signals, which are sent to your brain
Vibrating sound waves travel through the air, into the ear, making the eardrum vibrate
The eardrum vibrates the inner ear bones (anvil, hammer, and stirrup)
These vibrations then reach the cochlea, where they are changed to electrical impulses which travel to the brain

4. Hearing

5. Hearing
The small bones of the inner ear amplify the vibrations
Sound waves are collected by the ear lobe (pinna)
The auditory nerve takes the signals to the brain 6 4 1 2 3 5
The waves travel along the ear canal
The cochlea turns these into electrical signals
The waves make the ear drum vibrate
Using the worksheet label, and make the key notes, for how the ear works

6. Hearing
Complete the hearing worksheet, adding the key words which are missing, explaining how we hear

7. Hearing

8. How We Hear
Something vibrates to produce a sound. Sound travels through the air to the ear.
When the vibrations reach the eardrum they are transferred to the small bones, called the hammer, anvil and stirrup.
The bones pass the vibrations to the cochlea. This contains tiny hairs which change the vibrations to electrical signals, called impulses.
The auditory nerve takes the signals to the brain. We hear the sound when the message reaches the brain.

9. How Much
We hear a range of sounds from low pitch to high pitch – this is the audible range
The audible range is roughly between 20 Hz and 20,000 Hz (but different people have different audible ranges)
Many animals have a much wider range of hearing, such as dogs, dolphins and bats…

10. Damaging
The ear is very delicate (thin membranes and tiny bones which can be damaged easily)
Think of as many ways as you can which can cause damage to our ears
Your task is to produce a leaflet either listing the ways we can damage our hearing, or ways in which we can protect our hearing
It needs to be aimed at pupils you age – so think what is likely to affect your hearing!

11. Damaging
Consider
Ear getting blocked by wax (stops ear drum vibrating)
Loud bangs / accidents / infections can damage the ear drum (although it may repair itself)
Middle ear can get infected (antibiotics may help)
As people age the tiny bones in the inner ear can fuse together, preventing amplification of the vibrations so hearing worsens
Nerve cells in the cochlea sometimes fail, so the messages are not sent to the brain
Cochlea can be affected by loud noise (constant loud noises can causes hearing loss, and there is no treatment for this)

12. Tinnitus
Tinnitus - noises 'in the ears' and/or 'in the head' with no external source
Inner ear cells (these vibrate, changing sound vibrations to electrical impulses

13. Levels Constant loud noises can be extremely damaging to your hearing
Persistent levels above 90dB can result in hearing damage
Levels can be measured in decibels – more than 130dB will causes pain
Above 140dB even short exposure can results in hearing loss