I made this presentation to support a hearing impaired student in my class. The idea is to talk about what sound is, how we hear and about hearing impairments.

1. What is sound and how
do we hear it?
How are sounds made?
How does sound get from the source to your ears?

2. Sound is a type of energy made by vibrations.
When any object vibrates, it causes movement
in the air particles. These particles bump into the
particles close to them, which makes them
vibrate too causing them to bump into more air
particles. This movement, called sound waves,
keeps going until they run out of energy. If your
ear is within range of the vibrations, you hear
the sound.
http://www.sciencekidsathome.com/science_topics/what_is_sound.html

3. What is sound? Watch this movie to
find out!
Click this link if video does not play

4. The main points from the movie were:
- When sounds travel we are actually hearing how the vibrations affect
the air molecules
- Molecules squeezing and stretching through the air are what we call sound waves.
- Sound travels slower than light. That is why we see lightening before we hear
Thunder in a storm.
-Air molecules in a long tube vibrate more slowly, producing a lower pitch.
Air molecules in a short tube vibrate more quickly, producing a higher pitch.
-Pitch is measured by the number of vibrations per second. The faster the vibrations,
the higher the pitch.

5. • Sound waves travel through the air and enter the ear causing the ear drum to vibrate.
• The vibrations are processed in the ear in the cochlear, which sends messages to
our brain, and our brain interprets these as sound.
• If sound intensity is too great, or happens for a long period of time, the cells will die
at the beginning of the cochlear.
• High frequency sounds are heard by the beginning of the cochlear, and low
Frequency sounds are heard by the end of the cochlear.
• This is why many older people
cannot hear high frequency
sounds as well.
Just like Mr Murphy!
• Sound is measured in decibels. A quiet library is about 40 decibels, while a loud
rock band would be about 150 decibels.
I can’t
stand loud
music!!

6. How do we hear sounds?
1. Ear canal
2. ear drum
3. Hammer
4. anvil
5. Stirrup
8. Cochlea (inner ear)
9. The nerve of hearing
Sound waves
Enter the ear
canal
The ear drum vibrates and then the hammer, anvil and stirrup
vibrate sending the vibrations to the cochlea (inner ear).
The little hairs in the
cochlea move and they
change the vibrations
into a signal. This signal
is then sent to
the brain through the
nerve of hearing like a
message.
The brain interprets
this message for us –
and that is how we hear!
http://www.oticonchildren.com/children/com/Otikids/AboutHearing/HowDoesTheEarWork/index

7. Protect your hearing
Don’t listen to very loud sounds for long
periods of time.
The most significant single
cause of hearing loss in
Australia is exposure to
loud noise. 37% of hearing
loss is due to excessive
noise exposure.
http://www.hearing.com.au/upload/media-room/Hearing-loss-in-Australia.pdf

8. A hearing loss can result if
there’s a problem at any point
in the hearing pathway –
in the outer, middle or inner
ears, or in the complex auditory
nerve pathway to the brain. - present when you are born
- Acquired later, through illness ,
accident, exposure to chemicals or drugs
- Caused by a blockage or damage to the
Inner or outer ear, cochlea or auditory
(Hearing nerve)
Click here for more information on hearing loss in Australia
http://www.australiandoctor.com.au

9. Click here for more info on frequency and intensity of familiar sounds.

10. Soundwaves
See soundwaves in action!

11. One in six people in
Australia has a
hearning loss. With
the ageing of the
Australian population,
hearing loss is
projected to increase
to one in four
Australians by 2050.
http://suddenhearingloss.net/hearing-loss-symptoms/

12. Let’s make some sound with :
- A plastic cup
- A paperclip
- Some wool
- Some damp paper towel
Can you make the
Sound of a farmyard
animal using
these things????
Click here for the link to the experiment

13. How does it work?
The cup and string demonstration is
is an example of how a sounding
board works. The vibrations from the
string would be almost silent without
the cup, but when you add the cup, it
spreads the vibrations and amplifies
them (makes them louder.) Pianos
and music boxes use wood to act as a
sounding board to make the
instrument louder.

14. 5. Why does a flute have a higher pitch than a bass clarinet?
Task: Write down the answers to the following questions.
1. If someone asked you “What is sound?” how would you explain it?
2. In a thunderstorm, why do we see lightening before we hear thunder?
3.What is the unit of measurement for sound?
4. James listens to his ipod on full volume every day. How will this damage his hearing?
6. What are some causes of hearing loss?

15. A bone conductor is a
hearing aid
that allows you to
hear without sound
going through your
eardrums.
http://www.audioboneheadphones.com/howitworks.html

16. How It Works
Invented by Beethoven – Perfected by Audio Bone
How It Works
It is how we normally hear
We all hear sounds through both our bones and our ear drums.
Most sounds are heard by our ear drums.
The ear drum converts the sound waves to vibrations and transmits them to the
cochlea(or inner ear). But in some cases vibrations are heard directly by the inner
ear – bypassing your ear drums. In fact, this is one of the ways you hear your own
voice. This is also how whales hear.
Invented by Beethoven
Bone conduction was discovered by Ludwig van Beethoven,
the famous 18th century composer who was almost deaf. Beethoven found a way
to hear music through his jawbone by biting a rod attached to his piano.
Ludwig Van Beethoven 1770-1827
Click here for more information about bone conductor hearing aids