Sound

Sound Waves (Rdg Age 9-10?)

Sound is energy that we hear. Sounds begin with vibrations. Vibrations are caused when something moves back and forth very quickly. Vibrations travel through the air in all directions. We call these vibrations sound waves.

Our ears have three parts. Each part has a special job to help us hear sounds. The outer ear is the only part that we can see. It catches sound waves that then travel to the middle ear. The middle ear sends the sound waves to the inner ear. The inner ear changes the sound waves into signals that go to our brains. That‘s when sound is heard. Hearing happens very quickly.

Almost every animal has a body part that hears. Not all animals' ears are like ours. Birds don't have outer ears, and their middle ears are covered by feathers. Snakes only have inner ears, which are connected to their jawbones. This allows snakes to feel vibrations from the ground, where tasty food might be living.

Hearing Highs and Lows

Every sound has a pitch. The pitch of a sound is how high or how low the sound is. Study the graph. Each bar shows the lowest pitch to the highest pitch heard. The numbers are given in a measurement called hertz. Pitches over 20,000 hertz are too high for humans to hear.

Hearing

http://youtube.com/watch?v=flIAxGsV1q0

Sound Waves

http://youtube.com/watch?v=gE_p1StLSB4

1. To make a sound something must ..... *

• a) be hit
• b) move slowly through the air
• c) vibrate
• d) jump up and down

2. Explain why sound vibrations are similar to when you throw a stone into a puddle of water.

The reason why sound vibration are similar to when you throw a stone into water is because when you throw a stone in the water, when you chuck the stone in the air it is moving and making sound wave and then once it is in the water you can hear the stone drop into the water you can hear the movement of the stone and the water.    

3. What is the purpose of the graph?

• to compare the pitches of what living things hear
• To show the sounds that living things make
• To show the pitches that living things make.
• To compare types of living things.

4. People hear sounds in a range of about ____

• 20 - 20 000 hertz
• 10 - 50 000 hertz
• 10 - 10 000 hertz
• 20 - 20 000 hertz

5. Which of these can hear the highest pitch?

• a) Dogs
• b) People
• c) Grasshoppers
• d) Dolphins

6. Which of these can not hear the high pitched sound that people can hear?

• a) Dogs
• b) Grasshoppers
• c) Dolphins
• d) People

How does sound begin? (You also need to do some of your own research to write 2-3 sentences).

Sound begins once you talk or when something is hit and once you hit something it makes sound just like when you talk and then the sound travels to your ear which is called sound wave, so the sound waves travels to your outer ear, then to you inner ear and then goes to our brain. Then once we hear that sound again we will remember that sound again.

What are the three parts of our ears that help us hear? The outer ear, middle ear, inner ear.   Why are these parts so important? Each part has a special job to help us hear sounds.

Create an image of what sound waves might look like.