Sound

1
Sound
2

• Today you will learn
• How sounds are made and what they are.
• How we measure sounds
• How we can change sounds from high to low
• How sounds can travel in different materials
• How your ear works

3
The Importance of Sound
Sound helps us to understand the world around us.
When we speak or listen, messages are being sent
and also received. We are warned of danger when
gunshots or the screeching brakes of a car are
heard. We relax when we listen to peaceful
background sounds. Many sounds, eg music can give
us pleasure or comfort. Sounds therefore have
purpose. They can either be pleasant or
unpleasant to our ears. What do you hear ? Close
your eyes and listen to the sounds around you.
Try to identify them. Which sounds are pleasant
and which sounds are definitely unpleasant to
you?
4
How are Sounds Made?
When objects move backwards and forwards very
fast, they are vibrating. We call this movement a
vibration. Vibrations make sound. An example that
best explains this is when you use your vocal
cords when speaking. If you place a finger on
your throat, you will feel your vocal cords
moving. Sound is made because the air passing
through your vocal cords causes them to vibrate.
http//www.learn.co.uk/default.asp?WCIUnitWCU98
71
5
Watch a video at http//www.nidcd.nih.gov/health/
education/video/sound_vid.asp
What is sound? Sound is a form of energy, just
like electricity and light. Sound is made when
air molecules vibrate and move in a pattern
called waves, or sound waves. Think of when you
clap your hands, or when you slam the car door
shut. That action produces soundwaves, which
travel to your ears and then to your brain, which
says "I recognize that sound."
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
Measuring Sound
http//www.nidcd.nih.gov/health/education/video/lo
ud_vid.asp
http//www.nidcd.nih.gov/health/education/decibel/
decibel.asp
Scientists measure the loudness of sounds in
units called "bells", named after the inventor of
the telephone, Alexander Graham Bell. Talking
softly is about 30 decibels. Speaking in a normal
way is about 60 decibels. But an airplane, a boom
box, or a rock concert can be 100 to 140
decibels, and that is loud enough to cause a
permanent hearing loss.
10
Changing Sounds
http//www.bbc.co.uk/schools/revisewise/science/ph
ysical/15_act.shtml
We can tell the difference between sounds by
listening carefully to whether it is a high or
low sound. This is called the PITCH of the
sound. Remember A low sound is caused by SLOW
vibrations A high sound is caused by FAST
vibrations The BIGGER the vibration the louder
the sound The SMALLER the vibration the quieter
the sound Animal Sounds
http//www.learn.co.uk/default.asp?WCIUnitWCU98
72
11
How does sound Travel?
http//www.learn.co.uk/default.asp?WCIUnitWCU11
502
12
How do we hear sounds?
13
The Ear

• We use our ears to hear sounds all around us.
• Our ears help us learn new sounds.
• There are five parts to the ear.

14
The Five Parts of the Ear.

• The outer ear.
• The ear canal.
• The eardrum.
• The 3 bones of the ear.
• The cochlea.

15
1. The Outer Ear

• The outer ear collects sound waves and sends them
  to the ear canal. It is known as the Pinna

16
2. The Ear Canal

• The sound waves in the ear canal make the eardrum
  vibrate.

17
3. The Ear Drum

• Often called the eardrum because is resembles the
  skin stretched across a drum.
• The ear drum is only a fraction of a centimetre
  in size.
• The sound waves makes the drum vibrate.

18
4. The Three Bones of the Ear.

• The hammer
• The anvil
• The stirrup
• The bones are named for their shapes and are the
  smallest bones in the human body.
• These bones work to transport sound vibrations to
  the inner ear.

19
1. The Hammer

• The hammer is the first of the ears three bones.
• The sound vibrations move the hammer which in
  turn activates the anvil

20
2. The Anvil

• The anvil is the second bone of the inner ear.
• Its vibration moves the stirrup

21
3. The Stirrups

• The final and smallest bone of the ear is the
  stirrup.
• The stirrup passes the vibration through the oval
  window and into the inner ear.

22
The Cochlea

• A minute, bony, spiral shaped tube that looks
  like a snail shell. It has tiny hairs which sense
  the type of sound wave entering the ear
• The Cochlea sends the information to the brain
  through the auditory nerve.

23
Our brain then interprets the impulses into the
sounds we hear.
Can you label the different parts of the ear
24
Video of Ear
http//www.nidcd.nih.gov/health/education/video/tr
avel_vid.asp
25
Now try this quiz
http//www.nidcd.nih.gov/health/education/owlgame/
owl.asp
Brainpop Video and Quiz
http//www.brainpop.com/science/energy/sound/index
.weml?tried_cookietrue