Discussion on sound waves and the different properties of sound

1. MODULE 3:
SOUND
Prepared by: Sir Archie A. Duran

2. SOUND
produced when an object vibrates
based on the movement of particles,
it is classified as a LONGITUDINAL
WAVE.
based on the requirement for
medium, it is classified as a
MECHANICAL WAVE.

3. When we talk or make any
sound, our vocal cords
vibrate. When there are no
vibrations felt, no sound is
produced. This means
that sounds are caused by

4. Vibrations of molecules are
to the to-and-fro or back-
and-forth movement of
molecules. Vibrations are
considered as a
disturbance that travels
through a medium.

5. This vibratory motion
causes energy to
transfer to the air and
finally to our ears
where it is interpreted
by our brain.

6. CAN SOUND TRAVEL IN SOLIDS
AND LIQUIDS???
Of course...
In fact, the speed of sound varies in
different medium.

7. TO WHICH MEDIUM WILL
SOUND WAVES MOVE
FASTER???
consider the spaces between
particles

8. sound travels faster in solid than
in liquid.
and in liquid than in gas.
Since solid is the best
transmitter of sound, sound
travels fastest in solids and

10. Sound cannot travel in a
vacuum. Remember that sound
is a mechanical wave which
needs medium in order to
propagate. If no matter exists,
there will be no sound. In the
outer space, sound waves has no

11. Sound waves possess
characteristics common to
all types of waves. These
are frequency, wavelength,
amplitude, speed or
velocity, period.

12. OTHER PROPERTIES OF
SOUND
Pitch refers to the highness or
lowness of sound.
Loudness is how soft or how
intense the sound is as perceived by
by the ear and interpreted by the
brain.

13. THE GUITAR...

14. THE HUMAN EAR
Our ear and that of
animals are the very
sensitive sound
detectors. The ear is a
part of the peripheral
auditory system. It is
divided into three major
parts: the outer ear,
the middle ear and the

15. DID YOU KNOW???
Humans can only sense sound within the
frequency range of about 20 Hz to about
20000 Hz.
Vibrational frequencies beyond 20 000 Hz is
called ultrasonic frequencies while below 20
Hz are known as infrasonic frequencies.

16. Some animals like dogs can hear
sounds as high as 50 000 Hz while
bats can detect sounds as high as 100
000 Hz.

17. We can see images of your
baby brother or sister when
the OB-Gyne asks your
mommy or nanay to undergo
ultrasound.

18. It has also been found that
ultrasonic waves can be used
as rodent and insect
exterminators. The very loud
ultrasonic sources in a building
will usually drive the rodents away
or disorient cockroaches causing
them to die from the induced

19. INTENSITY VS LOUDNESS
Sound intensity is measured by
various instruments like the
oscilloscope.
Loudness is a psychological
sensation that differs for different people.

20. The unit of intensity
level for sound is the
decibel (dB), which
was named after
Alexander Graham
Bell who invented the
telephone.

22. MENTAL
EXERCISE

23. 1. Sound is produced
by the (_i_ra_i_n) of
objects.

24. 2. What unit is used to
express sound
intensity?
hint: named after Alexander

25. 3. Sound wave is
considered as
__________ waves
because it requires a
medium to be

26. 4. What part of the
human body can
detect sound waves?

27. 5. Humans can only
hear sound with a
frequency ranging
from 20 Hz to
__________ Hz.

28. 6. Give the 3 media
from which sound
waves can travel.

29. 7. Sound waves
travel faster in
________ than in
liquids and gases.

30. 8. __________ refers to
the highness or
lowness of sound.

31. 9. What do we call
sound waves that has
frequency lower than
20 Hz?

32. 10. What technology
involves the used of
sound waves to see
the baby inside the
mother’s womb?

33. 11. What instrument
is used to determine
sound intensity?

34. 12. In sound waves,
as frequency
increases, pitch
__________.

35. 13. In sound waves,
as frequency
decreases, pitch
__________.

36. 14. True or False
Sound can travel in
solid, liquid, gas, and
vacuum.

37. 15. What part of the
human body vibrates
that enable us to
produce sound and
communicate?

38. NEXT ADVENTURE:
LIGHT
WAVES