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Sound
Vibrations And Sound
Sound is
produced through vibration, moves in all directions
and
can be reflected.
These qualities
provide many benefits
to human beings when used properly. Sound helps life
to communicate with each other
.
6.1
Vibrations And Sound
Sound is produced by
vibration
from the source
Sound can be produced in several ways such as:
When the flute is
blown
, the air inside the flute vibrates
When the xylophone is
knocked
, the xylophone bar vibrates
When the strings of the guitar or violin are
plucked
or
bowed
, they vibrate.
The cymbal pieces will vibrate when
clapped
together
Sounds travel
Despite being in different positions, they could hear the sound of the police car siren because of the
sound waves moving in all directions
Sound can be reflected
When sound
hits a hard surface
, it will be
reflected
back
Example of sound reflection is in the picture above:
Screaming in the cave
Screaming in the empty hall
Sound reflection phenomenon
An
echo
is a sound produced when sound is reflected on a hard surface.
Ultrasound
is a sound that cannot be heard by humans but can be heard by animals such as bats, dolphins and whales to guide and track the location of their respective prey.
In medicine, ultrasonic sound reflection is used to detect organs in a patient’s body or fetus in the womb.
Sonar
is an ultrasonic sound reflection technology used to detect objects in water.
Useful and harmful sounds
The benefits of sound to everyday life:
Sound allows us to
communicate
Musical sound can be
entertaining
An ambulan siren indicates
emergency alert
Phone ringing
provides notification
on incoming calls
Sound loudness is measured in decibels (dB). Loud noises that exceeds 85 dB can damage our hearing.
Harmful noise, for example:
The noisy environment makes it
difficult to communicate
Excessive noise can
cause disturbance and stress
Frequent or excessive loud noise can cause
hearing problems
Reducing sound pollution
Noise that is too loud or unwanted can be reduced to be quieter or less clear.
Situations and ways to reduce noise pollution:
Airport ground staff use ear protectors to protect ear damage from the excessive aircraft noise.
Sound absorbers such as carpets, curtains and windows can reduce sound vibration.
The use of trees can help reduce noise pollution in our environment.
Vibrations And Sound
Sound is
produced through vibration, moves in all directions
and
can be reflected.
These qualities
provide many benefits
to human beings when used properly. Sound helps life
to communicate with each other
.
6.1
Vibrations And Sound
Sound is produced by
vibration
from the source
Sound can be produced in several ways such as:
When the flute is
blown
, the air inside the flute vibrates
When the xylophone is
knocked
, the xylophone bar vibrates
When the strings of the guitar or violin are
plucked
or
bowed
, they vibrate.
The cymbal pieces will vibrate when
clapped
together
Sounds travel
Despite being in different positions, they could hear the sound of the police car siren because of the
sound waves moving in all directions
Sound can be reflected
When sound
hits a hard surface
, it will be
reflected
back
Example of sound reflection is in the picture above:
Screaming in the cave
Screaming in the empty hall
Sound reflection phenomenon
An
echo
is a sound produced when sound is reflected on a hard surface.
Ultrasound
is a sound that cannot be heard by humans but can be heard by animals such as bats, dolphins and whales to guide and track the location of their respective prey.
In medicine, ultrasonic sound reflection is used to detect organs in a patient’s body or fetus in the womb.
Sonar
is an ultrasonic sound reflection technology used to detect objects in water.
Useful and harmful sounds
The benefits of sound to everyday life:
Sound allows us to
communicate
Musical sound can be
entertaining
An ambulan siren indicates
emergency alert
Phone ringing
provides notification
on incoming calls
Sound loudness is measured in decibels (dB). Loud noises that exceeds 85 dB can damage our hearing.
Harmful noise, for example:
The noisy environment makes it
difficult to communicate
Excessive noise can
cause disturbance and stress
Frequent or excessive loud noise can cause
hearing problems
Reducing sound pollution
Noise that is too loud or unwanted can be reduced to be quieter or less clear.
Situations and ways to reduce noise pollution:
Airport ground staff use ear protectors to protect ear damage from the excessive aircraft noise.
Sound absorbers such as carpets, curtains and windows can reduce sound vibration.
The use of trees can help reduce noise pollution in our environment.
Chapter : Sound
Topic : Sound
Year 4
Science
View all notes for Science Year 4
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