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Presentation on“ Noise
Barriers”
By:- VANDANA BHARTI
Noise barriers
Keeping the Noise Down
A sound occurs when an ear senses
pressure variations or vibrations in the air.
Noise is unwanted sound.
The brain relates a subjective element to a
sound, and an individual reaction is formed.
Highway traffic noise tends to be a dominant
noise source in our urban, as well as rural,
environment.
Noise "Noise is among the most
pervasive pollutants today. The problem with noise is not only that it is unwanted, but also that it negatively affects human health and well being. Problems related to noise include hearing loss, stress, high blood pressure, sleep loss, distraction and lost productivity, and general reduction in the quality of life."
Noise barrier
Noise barriers are solid obstructions built
between roadways and residential areas.
These barriers do not block all noise,
they only reduce the overall noise level.
Effective noise barriers typically reduce
noise levels by 5 to 10 decibels (dBA).
A 10 dBA increase in sound doubles the
perceived or apparent loudness of a
sound.
Reflection, Absorption and transmission at
a barrier
Sound transmission
Energy which is transmitted will give a rise to a new sound field on the other side of the boundary.
Sound absorption
The sound energy absorbed is usually the result of being converted into another form of mechanical energy which is generally heat and this may be achieved in several different ways.
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How effective are noise barriers?
When the line of sight is blocked
between the noise source and the
receiver, a reduction of a least 5 dBA is
achieved.
For each additional metre above line-
of-sight, a reduction of an additional 1.5
dBA is achieved.
How Does a Noise Barrier Work?
A noise barrier must be tall enough
and long enough to block the view of a
highway from the area that is to be
protected, the "receiver."
What Type of Material Is Best for a
Noise Barrier?
Material
concrete masonry wood metal foams
Noise Barrier
Research
Parallel Noise
Barrier
Effectiveness
Parallel Barrier
Effectiveness
Under
Free-Flowing
Traffic
Conditions
Performance
Evaluation
of Experimental
Highway
Noise Barriers
When are noise barriers required?
Ambient traffic sounds are everywhere, whether it is the daily hum of a busy street so loud that it limits normal conversation.
Traffic noise is the most pervasive and chronic noise to be faced in a growing urban region so heavily reliant on the automobile. For some, the volume and type of traffic close to their homes cause diminished home enjoyment.
Can Trees be planted as
noise barriers? In excess of 30 metres of dense coniferous
tree growth is required to achieve a 3 to 4
dBA reduction.
However, it is not feasible to plant enough
trees and other vegetation along major city
arterials to achieve such a reduction.
Plenum barrier
In the designing of a noise control
system for office and other buildings,
there are several important areas that
should be considered:
ceilings, glazing,
partitions, common ducting,
door, fixtures etc.
perimeter joints,
Why install a plenum barrier?
Light weight hung ceillings are generally made of
conventional sound absorbent material, such as
“acoustic the” which reduce sound reverberation
within the room.
These are ineffective as barrier and allow the sound
to pass through the plenum above the adjoining
areas.
To obtain sound privacy in an office hang a
plenum barrier from the concrete above the top of
the partition.
Type of adjustment for plenum barrier
www.allindustrialnoise.com
www.allindustrialnoise.com
www.allindustrialnoise.com
Plenum in ductwork
Heating and Cooling Essentials
Rectangular duct
Rectangular duct is 30-gaugc, galvanized sheet metal, and mainly used as a trunk line, or "extended plenum.
" Rectangular duct is widely used in the northeastern and northwestern parts of the United States.
It is used as a spacesaver and can be easily routed in overhead space between floor joists, or in an attic.
Branch lines consisting of round pipe come off the extended plenum to transport air to a register.
A branch line begins with a starting collar or
takeoff installed on the extended plenum.
The end of the extended plenum must be
blocked with an end cap that is anchored with
sheet metal screws and sealed with mastic.
Heating and Cooling Essentials
High transimission loss ceilings
Fiberglass Ceiling Tiles
Melamine Ceiling Tiles
Ceiling Clouds - Suspended Acoustic Solutions
www.allindustrialnoise.com
Fiberglass Ceiling Tiles Ceiling tiles are not only the top performs when
it comes to sound absorption and noise control
issues, but they are attractive and can help
"finish" off any room or office while absorbing &
blocking sound transmission.
www.allindustrialnoise.com
Melamine Ceiling Tiles Light, Flexible Ceiling Tiles Dramatically
Reduce Noise Levels in Any Room
With 5 unique surface designs to mix and match
acoustical ceiling tiles are ideal for any audio or
office setting.
www.allindustrialnoise.com
Ceiling Clouds - Suspended
Acoustic Solutions
Sizes: Standard up to
4' x 10'
Ceiling clouds are a
very effective treatment
for the reduction of
sound in ceiling areas. www.allindustrialnoise.com
www.allindustrialnoise.com
Acoustical foams
Melamine
Wedges
Linear
Wedges
V-Block
Wedges
Corner
Bass Trap
Anechoic
Wedges
Polyurethane
Melamine
Pyramid
foams
Pyramids
Polyurethane
Acoustical
foams
Pyramids Polyurethane These 2'x2' square,
open cell polyurethane acoustic foam panels have symmetrically identical beveled faces that disguise their seams from piece to piece.
Available in standard 2, 3 and 4 inch thicknesses
6 different colours,
they yield one uniform look to a treated wall space.
Ideal for any audio application where acoustics and aesthetics are both a must!
www.eNoiseControl.com
www.eNoiseControl.com
Melamine Pyramid foams
The Anechoic Wedge material is a lightweight,
porous, open cell, acoustic melamine foam
material designed for maximum sound
absorption where a Class 1 Fire rating is a must!
Resistant to most organic solvents, alkalis, and
diluted acids.
Heat resistant to 482F!
Most wall surfaces for controlling unwanted
sound reverberation within a room.
www.allindustrialnoise.com
Anechoic Wedges Polyurethane
• Class A Fire Retardant
• High Performance Absorption
• Fiber Free
• Anechoic Wedge Design
APPLICATIONS: For use in all
industrial, commercial, audio, OEM
and residential markets; Ceilings, walls
partitions, sound studios, radio stations,
band rooms, gyms, swimming pools,
gun ranges, mechanical rooms and
enclosures.
www.allindustrialnoise.com
Melamine Wedges
A lightweight, porous, open cell, acoustic
melamine foam material designed for
maximum sound absorption where a Class 1
Fire rating is a must! Resistant to most
organic solvents, alkalis, and diluted acids.
Heat resistant to 482 F!
www.allindustrialnoise.com
Linear Wedges
It is the most popular industrial noise source
absorber !
The featured contour profile helps trap industrial
sound sources in their wake!
This foam dissipates up to 80% of unwanted
sound.
Linear Wedge Polyurethane
Linear Wedge Melamine Grey
Linear Wedge Melamine White
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V-Block Wedges
These 12"x12" square polyurethane foam panels
are ideal for extreme noise sources,
low bass noise, impact noise, or for anechoic
sound chambers.
Available in standard thickness, with custom
thicknesses optional.
The ultimate in energy absorption with 100%
echo reduction
www.allindustrialnoise.com
Corner Bass Trap These 10" in •diameter acoustic COLUMNS are
ideal for portable sound absorption.
Available in 4' lengths, these fluted tubes of
self-standing acoustic foam are an ideal
compliment to our wall mounted Pyramids
Features:
» Open Cell Polyurethane Acoustical Foam
construction for maximum noise control.
www.allindustrialnoise.com
APPLICATIONS
• Audio/Video Recording Studios
• Churches & Meeting Halls
• Gyms, Cafeterias, Auditoriums & Pools
• Music Practice Rooms
• Entertainment Complexe
• Shooting Ranges
• Test Chambers
• Mechanical Equipment Rooms
• Computer Rooms
FEATURES
• Lightweight
• Easy Installation
• Variety of Colors Available
• Traps and Deflects Sound
• Standard Sheet Sizes: available for UPS shipping
• Unique Designs and Different Thicknesses allow customization and Sound Control precision
Damping Compound
Damping Compound is a sound deadener that consists of filled asphaltic mastic acoustical sheet material.
This material is designed for cost effective vibration damping by effectively reducing the resonant vibration of sheet metal panels that radiate noise when exited by motor vibration or struck by other materials.
The vibration dampening compound reduces the noise upon impact and the duration of the noise created.
Typical applications are:
motor driven equipment casings
chutes
hoppers
bins
sheet metal ducts
material handling containers.
www.eNoiseControl.com
