soundenergy-170307173256.ppt

1. Sound Energy
Made by Dr. Soha Bedair

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. Sound creates :
 Compressions & rarefactions:

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

5. 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.

6. Volume:
 It is measured using sound level meter
 The unit for measuring the volume is
decibels(dB)

7. How does sound travel?
 Sound passes through the medium as
longitudinal waves.
 While light travels by transverse waves

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

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

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

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

12. Pitch, frequency and amplitude:
 Pitch: it determines how high or low the
sound is.
is produced by short objects. is produced by long obj.
tight( stretched)objects. Loose obj.

13. Frequency:
 It is number of vibrations in one second.
 As the number of vibrations increases the
frequency and pitch increases.

14. Louder
Softer
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.

15. Echo & how the sound energy is
absorbed:
 Echo: is when the sound bounces back from
a hard surface.
 If sound hits soft surface is absorbed
more>>>> than hard surfaces.

16. How is sound transmitted?
 The sound waves have energy.
 The sound waves needs a matter to be
transmitted.(solid, liquid or gas).
 We call the matter (medium).

17. Sound transmission through
different media:

18. Parts of the ear:
cochlea

19. How we hear a sound?
 When the sound wave reaches our ear drum, it hits it
and our ear drum starts to vibrate.
 Then the three bones attached to the ear drum starts
to vibrate.
 The cochlea then translates these vibrations into
signals.
 The brain receives those signals by nerves.
 Then the brain translates these signals into sound.