Sound Waves Propagation of sound Characteristics of Sound Properties of Sound

1. SOUNDS
 Propagation of Sound
 Characteristics of Sound
 Properties of Sound

2. SOUND
Consists of waves of air particles.
is composed of waves of compression
and rarefaction in which the human ear
is sensitive.
 is produced when a vibration causes
pressure variations in the medium

3. SOUND WAVE
Are longitudinal waves—compressions
and rarefactions that travel through a
medium.
The size of a compression indicates
how much energy the sound wave has.

4. TYPES OF WAVE
1. TRANSVERSE WAVES
-occur when the individual particles or segments
of a medium vibrate from side to side
perpendicular to the direction in which the
waves travel.
2. LONGITUDINAL WAVES
-occur when the individual particles of a medium
vibrate back and forth in the direction in which
the waves travel.

5. HUMAN HEARING

6. PROPAGATION OF SOUND
MEDIUM
- material that sound waves can travel
through.
- it can travel through solids, liquids,
and gases but not through a vacuum.
*sounds possess the characteristics
and properties that are common to all
waves.

7. CHARACTERISTICS OF WAVES

8. CHARACTERISTICS OF WAVES
1. Crest and Trough – Highest point and
lowest point of wave.
2. Amplitude – is the maximum displacement
of a vibrating particle of the medium on either
side of its normal position when the wave
passes.
3. Wavelength – is the distance between
adjacent crest or trough.
4. Frequency – the number of waves that pass
particular point every one second.
5. Period – the time required for one cycle, a
complete notion that returns to its starting

9. CHARACTERISTICS
OF SOUND

10. 1. PITCH
- highness or lowness of a sound.
a. FREQUENCY
- the greater the frequency, the higher the
pitch.
Hertz (Hz) – unit to measure frequency
and pitch.
Audio Frequency range
- frequency ranging 20 Hz to 20 000 Hz
Infrasonics
- Frequency below 20 Hz.
 Ultrasonic Frequencies
-vibrational frequencies beyond 20 000 Hz.
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11. 2. LOUDNESS and INTENSITY
- description of how high or low the
sound seems to a person.
- determine mainly by the amplitude of
the sound.
a. Decibel (dB) – unit used to measure
sound intensity or loudness.
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14. *Intensity is measured by various
instrument like the oscilloscope.
Logarithmic scale
-is used to describe sound intensity
which roughly corresponds to
loudness.
3. TIMBRE or QUALITY OF SOUND
- tone color or tone quality
- use to distinguish between two
different sounds that have the same
pitch or loudness
- it helps to identify what sound
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15. 4. SPEED OF SOUND
Depends on:
1. Type of Medium
2. Temperature of Medium
3. Density
4. Elasticity

16. 1. Type of Medium
2. Temperature of medium
- travels faster to higher temperature.
3. Density
- sound moves well through dense materials.
4. Elasticity
- tendency of a material to maintain its shape and
not deform when force is applied to the object or
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SOLID LIQUID GAS

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19. PROPERTIES OF
SOUND

20. REFLECTION OF SOUND
Reflection
- is usually described as the turning
back of a wave as it hits a barrier.
Ex. Echo
Reverberation refers to the multiple
reflections or echoes in a certain
place.
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21. REFRACTION OF SOUND
Refraction
- is described as the change in speed of
sound when it encounters a medium of
different density.
- This change in speed of sound during
refraction is also manifested as sort of
“bending” of sound waves.
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22. DIFFRACTION OF SOUND
Diffraction
- involves a change in direction of waves
they pass through an opening or around a
barrier in their path.
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23. DOPPLER EFFECT
-- is the apparent change in the
frequency of a sound caused by the
motion of either the listener or the source
of the sound.

24. SONIC BOOM
-- happens when the aircraft or any
vehicle breaks the sound barrier while it
accelerates and outruns the speed of
sound.
*A loud explosive sound is heard on the
ground and is called a sonic boom.
Supersonic