NOISE POLLUTION

• What is Noise Pollution?

• Sources of Noise Pollution

DISCUSSION
OUTLINE • Effects of Noise Pollution

• Noise Pollution Control

Technologies
 INTRODUCTION
• One of the pollutants that can be present in all aspects of the
environment is noise

• Noise pollution is perhaps one of the pollutions that is not talked

about widely

• In this section, we’ll be expanding our knowledge regarding noise

pollution by discussing the causes, effects, and control technologies
WHAT IS NOISE
POLLUTION?
 NOISE POLLUTION
• Noise pollution is the unwanted or excessive sound that can have
deleterious effects on human health and environmental quality

• Noise pollution is commonly generated inside many industrial

facilities and some other workplaces, but it also comes from highway,
railway, and airplane traffic and from outdoor construction activities

• It can even be caused by ships which can be considered as noise

pollution underwater that could affect all life forms in bodies of water
 • Sound waves are vibrations of air molecules
carried from a noise source to the ear
• It is described in terms of loudness
(amplitude) and pitch (frequency) of the wave
• Loudness (Sound Pressure Level, SPL) is
measure in decibels (dB)
MEASURING • The human ear can detect sound between
LOUDNESS 0 dB to 140 dB with sound between 120 – 140
dB being the pain threshold
• A library can have an SPL of 35 dB, moving
bus or train can have 85 dB, building
construction can generate 105 dB
• SPLs decreases with the distance from the
source
According to the World Health Organization, sound levels
less than 70 dB are not damaging to living organisms,
regardless of how long or consistent the exposure is
 • Sound Intensity is the rate at which sound is
transmitted
• The decibel is a logarithmic measure therefore:
• 10 dB increase means 10x increase in intensity
• 20 dB increase means 100x increase in intensity
• 30 dB increase is 1000x increase in intensity
MEASURING • When sound intensity is doubled, there only 3 dB
increase in SPL
LOUDNESS • A drill operated will produce 90 dB of sound. If
two of the same drill is operated, it will only
account to 93 dB of sound
• Two sounds differing more than 15 dB are combined
the louder sound will drown out the weaker sound
• If a compressor 80 dB drill and a 95 dB dozer
are operating at the same site, the net SPL will
be 95 dB
 SOURCES OF
NOISE POLLUTION
 SOURCES OF NOISE
POLLUTION
INDUSTRIAL SOURCES
• Industrialization has resulted in the rise of noise pollution
• Most industries use heavy machines capable of producing very high
levels of noise
• They have equipment such as compressors, exhaust fans, grinding
mills, and generators which increase the overall noise levels in the
environment
• Workers in these environments are in great health risks in case they
do not take proper measures.
• This would include construction sites
 SOURCES OF NOISE
POLLUTION
TRANSPORTATION
• The transportation industry is a big source of environmental noise in
urban regions
• People caught in traffic jams are also often impatient and will
continuously hoot their horns to alert the driver in front of them to
move
• These acts produce unbearable noise to the people living in the
neighboring areas, the commuters or passersby, and the environment
as a whole
• Airplanes also increase the problem of noise in major urban cities
• The jet-planes taking off and landing in such areas normally produce
high sound levels.
 SOURCES OF NOISE
POLLUTION
POOR URBAN PLANNING
• Developing nations habitually lack proper urban planning that leads to
congested housing, small spaces, small industry proliferation, and
lack of enough parking areas

• Poor urban planning thus contributes to environmental noise through

fights or social and basic amenities, noise from small manufacturing
industries, wrangles over parking space, family quarrels from the
neighboring houses, and noise from playing children.
 SOURCES OF NOISE
POLLUTION
PUBLIC EVENTS
• Public functions such as rallies, strikes, elections, religious and
secular events use addressing systems that are very loud
• The organizers of such events normally ignore the rules set against
public noise pollution by the stat
• Loud noise from public address systems and music systems during
social events such as parties and religious crusades are another
source of noise pollution
• Open markets also often produce high levels of noise pollution due to
the activities of buying and selling, and the use of loudspeakers and
megaphones in advertising merchandise or services
 SOURCES OF NOISE
POLLUTION
AGRICULTURAL MACHINES
• Noise level of as high as 90 dB to 98 dB has been recorded in some
farms using heavy types of machinery and equipment

• These equipment include thrashers, tube wells, tractors, drillers,

powered tillers, and harvesters
 SOURCES OF NOISE
POLLUTION
MILITARY EQUIPMENT
• Artillery tanks, rocket launching, military airplanes drills, explosions,
and shooting practice are serious noise polluters

• Deafening impacts are produced by the sounds of jet engines and in

extreme cases, they cause the shattering of windowpanes and
cracking of old dilapidates buildings located near their take-off and
landing areas or when they fly past such structures
 SOURCES OF NOISE
POLLUTION
INSIDE BUILDING SERVICES
• Construction works, workshops and automobile repairs cause noise
pollution

• The equipment used in such jobs produces a lot of noise that causes
nuisance and may hamper hearing ability
 SOURCES OF NOISE
POLLUTION
HOUSEHOLD ACTIVITIES
• These are activities such as the loud banging of doors, noises from
playing children, furniture movement, crying infants, loud arguments
• Many households also own entertainment equipment such as Hi-Fi
Systems, Television sets, and loudspeakers that may further
contribute to the overall noise emanating from indoor household
activities
• Household equipment like pressure cookers, vacuum cleaners,
washing machines, sewing machines, mix-grinders, desert coolers,
exhaust fans, and air-conditioners equally produce a lot of noise
 SOURCES OF NOISE
POLLUTION

OFFICE EQUIPMENT
• In offices, there are printers, photocopiers, and typewriters among
other equipment that contribute to noise pollution in the working
places and its environs
 SOURCES OF NOISE
POLLUTION
SHIPS
• Any ships operating in the ocean produce sound underwater
• The noise produced by the rotors or any machine operating the
vessels could cause damage to life forms present underwater
• Ships using underwater to map out hydrogeological formation on the
seafloor could also affect those underwater animal using sonar to
communicate with each other (i.e. Dolphins)
• Take note that since liquid molecules are closer compared to
molecules in air, sound travels faster and is perceived louder by
underwater wildlife
 EFFECTS OF
NOISE POLLUTION
 EFFECTS OF NOISE
POLLUTION – HUMANS
DAMAGED BRAIN AND HEARING POWER
• High-intensity sound waves cause unnecessary ripples in the ear canal,
disturbing the fluid that aid communications between the ear and the brain
• This disturbance destroys the tiny, very delicate, hair follicles that send
signals to the brain whenever sounds enter the ear.
• Hearing loss is very probable after 50% of these hairs are gone,
necessitating hearing devices, particularly for children
• Research has also shown that uncontrolled exposure to high-intensity
noises can seriously jeopardize a kid’s memory and reading power.
 EFFECTS OF NOISE
POLLUTION – HUMANS
INCREASES RISK OF CARDIOVASCULAR DISEASES
• Being exposed to noise pollution for ten consecutive years or more
raises your chances of suffering from at least one cardiovascular
disease later in life by 300%
• Scientists from the University of Gothenburg found out that high noise
levels increase an individual’s pulse rates and cause constriction of
blood vessels, thus making him/her vulnerable to heart attacks or
high blood pressure
• Being exposed to such noises for more than 8 hours a day could even
be worse.
 EFFECTS OF NOISE POLLUTION –
HUMANS
POOR SLEEP
• In a noisy neighborhood, you know how irregular sleep can get on a
noisy night
• The danger of not sleeping well at night is that your day gets boring,
you get tired early, and you are forced to forego most energy-draining
activities
• Poor sleeping patterns can also cause serious cardiovascular
problems in the long run
 EFFECTS OF NOISE
POLLUTION – HUMANS
PSYCHOLOGICAL DISORDERS
• The noises you ‘got used to’ can lead to serious psychological disorders and,
sadly, you may not even realize it because it becomes a part of you.
• Research shows that too much noise makes people easily irritable,
nervousness, irrational in decision making, and constant unease throughout
the day
• In extreme cases, noises can make your life so stressful that you become
socially aloof, unproductive at work due to poor concentration, and
emotional instability due to reduced self-confidence
• Without the help of those around you, you might end up developing an
unlikeable, socially suppressive personality without knowing it
 EFFECTS OF NOISE POLLUTION –
HUMANS
INTERFERING WITH SPEECH
• Conversing in a noisy environment is almost impossible

• Working with noisy machines, for example, affects your inter-social

life and makes your days seem longer than they are
 EFFECTS OF NOISE
POLLUTION – WILDLIFE

• Noise pollution affects not only

human but even wildlife
• Noise can have detrimental
effects on animals, increasing
the risk of death by changing
the delicate balance in
predator or prey detection and
avoidance
• Sound waves from noise
pollution can also affect their
communication especially in
relation to reproduction and
navigation (i.e. bats, dolphins,
whales, etc.)
 EFFECTS OF NOISE
POLLUTION – WILDLIFE
• Stranding of whales and dolphins
• Extremely loud sound may cause hearing damage in marine animals
• Disruption of the schooling structure of fish or impaired growth of
shrimp
• Noise means stress and impairs the animals’ immune system which
makes them more susceptible to illness in general
• Ocean noise pollution also causes marine animals to flee and abandon
valuable habitats, either because of direct impact or because they
must follow their fleeing prey
• Disruptive impact on mating, finding food and nursing young
 EFFECTS OF NOISE
POLLUTION –
WILDLIFE

• European robins living in urban

environments are more likely to
sing at night in places with high
levels of noise pollution during the
day, suggesting that they sing at
night because it is quieter, and
their message can propagate
through the environment more
clearly
 EFFECTS OF NOISE
POLLUTION –
WILDLIFE
• Zebra finches become less faithful
to their partners when exposed to
traffic noise. This could alter a
population's evolutionary trajectory
by selecting traits, sapping
resources normally devoted to
other activities and thus leading to
profound genetic and evolutionary
consequences
 EFFECTS OF NOISE
POLLUTION – WILDLIFE
• Animals such as whales that depend on sound for communication can
be affected by this noise in various ways

• Higher ambient noise levels also cause animals to vocalize more

loudly, which is called the Lombard effect

• Researchers have found that humpback whales' song lengths were

longer when low-frequency sonar was active nearby
 EFFECTS OF NOISE
POLLUTION – WILDLIFE

• Noise pollution may have

caused the death of certain
species of whales that
beached themselves after
being exposed to the loud
sound of military sonar
• Even marine invertebrates,
such as crabs (Carcinus
maenas), have been shown
to be negatively affected by
ship noise
 NOISE POLLUTION
CONTROL TECHNOLOGIES
 NOISE POLLUTION
CONTROL TECHNOLOGIES
THE SOURCE-PATH-RECEIVER MODEL
• One effective way to reduce the perceived noise is to understand the
Source-Path-Receive Model

• May it be a commercial building, industrial facility, or even a

residential home, the principle remains the same, start by looking at
all the possible sources of noise and then look at all the possible
entry points, or pathways, for the sound to travel

• That list includes the roof, windows and doors, and wall assemblies
 NOISE POLLUTION
CONTROL TECHNOLOGIES
SOURCE
• Promote and design quieter equipment

• Physical materials, such as foam, absorb sound and walls to provide a

sound barrier that modifies existing systems that decrease hazardous
noise at the source

• Sources may be modified, redesigned, relocated or isolated

 NOISE POLLUTION
CONTROL TECHNOLOGIES
SOURCE – Sound Insulation
• Prevents the transmission of
noise by the introduction of a
mass barrier

• Common materials have high-

density properties such as brick,
thick glass, concrete, metal etc.
 NOISE POLLUTION CONTROL
TECHNOLOGIES
SOURCE – Sound Absorption
• Sound absorption: a porous material
which acts as a ‘noise sponge’ by
converting the sound energy into heat
within the material

• Common sound absorption materials

include decoupled lead-based tiles, open
cell foams and fiberglass
NOISE POLLUTION CONTROL
TECHNOLOGIES

SOURCE – Vibration Damping

• Applicable for large vibrating
surfaces like chutes,
hoppers, machine guards,
panels, conveyors, etc.
• The damping mechanism
works by extracting the
vibration energy from the thin
sheet and dissipating it as
heat
NOISE POLLUTION CONTROL
TECHNOLOGIES

SOURCE - Vibration Isolation

• Prevents transmission of vibration
energy from a source to a receiver
by introducing a flexible element or a
physical break

• Common vibration isolators are

springs, rubber mounts, cork etc.
 NOISE POLLUTION
CONTROL TECHNOLOGIES
PATH
• The principle of noise reduction through pathway modifications
applies to the alteration of direct and indirect pathways for noise.
• Noise that travels across reflective surfaces, such as smooth floors,
can be hazardous.
• Pathway alterations include sound dampening enclosures for loud
equipment and isolation chambers from which workers can remotely
control equipment while removed from noise
• These methods prevent sound from traveling along a path to the
worker or other listeners
 NOISE POLLUTION
CONTROL TECHNOLOGIES
RECEIVER
• Administrative controls, such as the restriction of personnel in noisy
areas, prevents unnecessary noise exposure

• The receiver end is also the part of the model where different
personal protective equipment are employed to further minimized the
intensity of sound waves received by the eardrums

• Isolation of the receiver could also help in minimizing the sound

intensity perceived
 SYNTHESIS
AS MENTIONED, NOISE POLLUTION IS ONE PROBLEM THAT IS NOT
WIDELY TALKED ABOUT

HOWEVER, ITS NEGATIVE IMPACT TO BOTH HUMANS AND

WILDLIFE HAS BEEN VERY EVIDENT ESPECIALLY NOW

IMPACTS CAN BE LESSENED THROUGH THE AWARENESS OF THE

SOURCES OF NOISES THAT ARE CONSIDERED DISTURBANCE

IF THESE SOURCES ARE IDENTIFIED, SOLUTIONS CAN BE PLOTTED

TO HELP IMPROVE OUR WAY OF LIVING
~DAS ENDE~