A sound is made by something vibrating, that is moving forwards and backwards very fast. When you talk your vocal chords make the air beside them vibrate. These vibrations then travel to the ear of the person listening; the listener’s eardrums feel the vibrations and send the ‘message’ to the brain.
Some sounds are low, and some sounds are high. The faster something vibrates the higher the pitch of the sound.
Red Fox
A fox has much better hearing than humans. This helps it to find prey more easily.
Copyright Mike BrownRed Fox
Copyright Mike Brown
Copyright Mike Brown
Red Fox
A fox has much better hearing than humans. This helps it to find prey more easily.
Copyright Mike Brown
Dogs, rats and other animals can hear sounds of much higher pitch than humans.
Astronaut on the Moon
Courtesy of NASA
Courtesy of NASA
Sound needs something to pass on the vibrations. There is no sound in Space because there is no air to pass on the vibrations. Astronauts talk to each other by radio.
Dolphin
A dolphin swimming a green sea.
Dolphin
Dolphin
A dolphin swimming a green sea.
Sound travels better through water than through air; dolphins can hear each other over very long distances. Sound travels better still through solids.
Sound, like light, can bounce back, especially off a smooth hard surface. This is called an echo. Submarines often use echoes to find out what is under the water.
Ears are sensitive and can be easily damaged by loud sounds. So be very careful when using your ipod or MP3 player. Do not play them too loud or you may have a hearing problem when you are older.
For lots more information and activities on SOUND, you can look up the section on Sound in the Learning Zone.