2. 1. FREQUENCY
• Refers to the number of waves that are produced by a sound at a given
time.
• It is measured in units called hertz (Hz).
• Sound waves that have a high frequency tend to emit a high pitch.
• PITCH is the highness or lowness of a sound (ex: high pitch – chirping of
bird; and low pitch – mooing cows).
• Ex: sound of breaking glass produces high-pitched sound; a bass drum
has a low frequency and produces a low-pitched sound.
• Human ear is able to perceive sound frequencies from about 20 to 20 000
Hz, higher or lower than this range can no longer be heard by humans.
3. • Ultrasonic sound –
frequency greater than 20
000 Hz, dogs can hear this
sound and this is one reason
why dogs come in handy
when it comes to guarding
your house.
• Infrasonic sound – frequency
less than 20 Hz, sound of
rumbling of thunder, your
arms swinging in the air,
earthquakes and ground
tremors, and even elephant
grunts have frequency that
are very low for you to hear.
4. 2. INTENSITY
• amount of energy that sound carries in a given time.
• Volume which means the loudness and softness of a sound can identify if
there so much energy carried by a certain sound.
• Strong vibrations produces louder sound, for instance, striking your
hands together.
• Weaker vibrations produce softer sound, for instance, clapping the
hands more gently.
• Louder sound carries a lot of energy, fainter/softer sound carries little
energy.
• Decibel (dB) scale is used by scientist to measure theintensity of a sound.
5. • 0 dB – soft, barely be
heard
• 200 dB –
tremendously loud
like the rocket
engine, exposure to
this decibel will result
to permanent
deafness
6. 3. TIMBRE
• sound quality.
• Ex: guitar produces a sound that has a different quality from a flute. Both of
them, when played by a trained musician, will produce harmonious sound.
• What causes?
• A sound is called music if it has a pleasing quality, a definite and
identifiable pitch, and a repeated timing called rhythm.
• Music is one of the practical applications of the concept of sound. People
long ago have used music as a part of their culture and tradition. Some
ethnic groups in the Philippines invoke the spirits through music to ask
blessings, good weather, fertility of the soil, and bountiful harvest.
7. EFFECTS OF SOUND ON PEOPLE
Causes the object to move, since sound is a form of energy.
Loud sounds can cause certain objects to vibrate and shiver. Loudspeakers
placed near a glass windows can cause an individual pane of window to
vibrate. Try placing a glass filled with water right next to a boom box or a
guitar amplifier. As soon as loud sound is produced by the speakers of the
boom box or amplifier, you will see the water inside the glass vibrate and
create ripples.
8. EFFECTS OF SOUND ON PEOPLE
Pleasant sound like music played softly can relax you and make you feel
good.
Exposure to loud sound and noise can cause health risks. Causes: stress,
hearing loss, and sleeping difficulty. Too much noise heard over a period of
time causes impairment of hearing. Prolonged exposure to impulsive noise
can damage one’s ears that may result in permanent loss of hearing. Health
effects may include anxiety and stress and in extreme cases, fright.
Ex: hearing the incessant blare of a fire truck’s siren throughout the night
can leave people – especially the elderly – stressed and tired the next
morning.
9. PREVENTING THE BAD EFFECTS OF
SOUND:
1. Construction of soundproof rooms
for noisy machines in industrial and
manufacturing installations must be
encouraged. This is also important for
residential buildings having
appliances and devices that produce
loud sounds.
10. PREVENTING THE BAD EFFECTS OF
SOUND:
2. The use of horns with jarring sounds, motorbikes with damaged exhaust
pipes, and noisy trucks should be minimized.
3. Noise-producing industries, airports, bus and other transport terminals, and
railway stations should be sited far from living places.
4. Community law enforcers should check the misuse of loudspeakers in
worship services, outdoor parties, and discos, as well as in public
announcement systems.
5. Community laws must impose silence zones near schools, hospitals, and
similar places.
11.
12. PREVENTING THE BAD EFFECTS OF
SOUND:
6. Planting trees along roads and in residential areas is a good way to reduce
noise pollution as trees absorb sound.
