Sound is a form of energy created by vibrations that travel through matter as longitudinal waves. When an object vibrates, it causes the surrounding air particles to move and bump into each other, transferring the vibrations. The pitch of a sound depends on the speed of these vibrations, with higher pitches associated with faster vibrations. Musical instruments produce sound through different means, including blowing into woodwinds, plucking or strumming strings, striking percussion instruments, and buzzing lips into brass instruments.

1. Sound Energy

2. What is sound?
 Sound
is
–
A form of energy made by vibrations.
–
When an object vibrates it causes the air particles
around it to move.
–
These particles bump into particles close to them
and this continues until they run out of energy.

3. Try this:
 Put
your finger on your neck and say “aah”
as loud as you can.
 Now
 You
say it as soft as you can.
can not only hear the sound, but you can
feel the vibration inside your throat.

4. How does sound travel?
 Sound
travels through all forms of matter—
gases, liquids and solid.
 These
are called the medium.
 Sound
cannot travel through a vacuum.

5. What is pitch?
 Pitch
is how high or how low a sound is.
 This
is a high pitched sound.
 This
is a low pitched sound.

6. How does sound travel?
 Sound
passes through the medium as
longitudinal waves.
 When the vibrations are fast you hear a
high pitch. When they’re slow, you hear a
low pitch.
High Pitch
Low Pitch

7. How else can we change sound?
 We
can make it louder or softer by changing
the amplitude of the height of the wave.
 The higher the amplitude, the louder the
sound. The lower the amplitude the softer
the sound.
Louder
Softer

8. How do musical instruments create
sound?
 It
depends on the type of instrument. There
are four types.
–
–
–
–
Woodwind
String
Percussion
Brass

9. Woodwinds Instruments
 Woodwinds
make music by blowing on the
top of the instrument or on a reed.
Clarinet
Bassoon
Oboe
Flute
Piccolo

10. String Instruments
 Strings
make music by plucking or
strumming the strings.
Cello
Guitar
Harp
Violin
Electric
Guitar

11. Percussion Instruments
 Percussion
instruments make music by
striking, shaking or scraping them.
Tambourine
Piano
Drum
Cymbals
Xylophone
Maracas

12. Brass Instruments
 Brass
instruments make music by buzzing
lips while blowing.
Trombone
French Horn
Tuba
Trumpet

13. Did you know?
 Sound
travels 4 times faster through water
than through air.
 There
is no sound in space.
 Geologists
use their knowledge of how sound
travels through rocks to help them find oil
fields.