Unit 3 Acoustic Materials.pptx.pdf

Building Material & Science-V
B.Arch 5th
Semester Faculty:Ar. Ashwani Singh
Acoustic Materials
Unit-3 Acoustic Materials
• Properties of Acoustic Materials
• Various Acoustic Materials used in Buildings Components-Wall, Roof etc
• Environmental Impact Evaluation of Manufacturer & Use of Acoustic
Materials

B.Arch 5th
Acoustic Materials
Acoustics
Acoustics, the science concerned with the production, control, transmission, reception, and
effects of sound. The term is derived from the Greek akoustos, meaning “heard.”
Acoustic Materials
Acoustical materials are those materials designed and used for the purpose of absorbing sound
that might otherwise be reflected. They may compose of variety of foams, fabrics, metals, etc.
used to quiet workplaces, homes, automobiles, and so forth to increase the comfort and safety
of their inhabitants by reducing noise generated both inside and outside of those spaces
Properties of Acoustic Materials
Properties of Acoustic Material to solve the workplace sound related problems by:
• Absorb - Sound Absorbers
• Diffuse - Sound Diffusers
• Block - Noise Barriers
• Divert - Sound Reflectors

B.Arch 5th
Acoustic Materials
Acoustic Materials may be classified as :
1. Sound Absorbers
2. Sound Diffusers
3. Noise Barriers
4. Sound Reflectors
Behaviour of Sound:
• Sound is reflected, transmitted, or absorbed by the materials it encounters.
• Soft surfaces, such as textiles, and fibre glass, tend to absorb sound waves, preventing
them from further motion.
• Hard surfaces, such as ceramic tile, gypsum board, or wood, tend to reflect sound
waves, causing ‘echo’. Reverberation is the term used to describe sound waves that
are reflected off of surfaces.
• Dense, massive materials, such as concrete or brick, tend to transmit sound waves
through the material.

B.Arch 5th
Acoustic Materials
It is very important to distinguish between sound absorption and sound transmission loss.
Sound absorbing materials control sound within spaces and function by allowing sound to pass
through them relatively easily. They are generally porous and absorb sound as a result of many
interactions. Conversely, a material or system, that provides a good sound transmission loss is
usually non-porous and a good reflector of sound.
Methods of Sound Absorption:

B.Arch 5th
Acoustic Materials
Sound Absorbers:
Sound waves will do one of two things when they encounter an object – they can be absorbed,
or they can be reflected. When sound is reflected, it is sent back into the room. When it’s
absorbed by a sound-absorbing material, it turns into a small amount of heat energy. Acoustics
science involves finding the right balance between absorption and reflection.

B.Arch 5th
Acoustic Materials
Sound Absorbing Materials:
1. Acoustical Foam Panels-Intro
Acoustic foam is an open celled foam used for acoustic treatment. It attenuates airbone sound
waves, reducing their amplitude, for the purposes of noise reduction or noise control. The
energy is dissipated as heat. Acoustic foam can be made in several different colors, sizes and
thickness. Acoustic foam can be attached to walls, ceilings, doors, and other features of a room
to control noise levels, vibration, and echoes. Many acoustic foam products are treated
with dyes and/or fire retardants.

B.Arch 5th
Acoustic Materials
Acoustical Panels-Properties
Acoustic foam is a lightweight material made from polyurethane foam either polyether or
polyester, and also extruded melamine foam. It is usually cut into tiles - often with pyramid or
wedge shapes - which are suited to placing on the walls of a recording studio or a similar type of
environment to act as a sound absorber, thus enhancing the sound quality within a room.
Acoustic foam reduces or eliminates echoes and background noises by controlling
the reverberation that sound can make by bouncing off walls.
Acoustical Panels-Types
Wedge Acoustic Foam Pyramid Acoustic Foam Square Grid Quadritic Residue

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Acoustic Materials
Acoustical Panels-Fixing Details

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Acoustic Materials
2. Acoustical Fabric Panels
Acoustic Fabric Panels are made of wood frame wrapped in fabric with some other sound
absorber, such as high-density fiberglass, glasswool or foam.

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Acoustic Materials
3. Sound Absorbing Under Layment
Sound Absorbing Underlayment materials could be foam, vinyl, rubber. They are dense and they
can provide sound absorption as well as soundproofing. Generally, they are applied between
subflooring (usually concrete or plywood) and flooring (could be hardwood or laminate).
This material comes in various forms, such as acoustic foam, felt, plywood, but felt is one of the
best solutions because it is very effective in reducing sound absorption.

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Acoustic Materials
4. Acoustic Partition
Acoustic partitions could serve for different purposes, and they could be lightweight or
heavyweight, which are usually made of 100% polyester. Since lightweight ones are easy to
move around, they could be used to divide a room.

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Acoustic Materials
5. Acoustic Mineral Wool
Acoustic mineral wool is of double usefulness because it may serve for both sound absorption
and soundproofing. Also, it is tolerant of high heat as well as water, which means that it is
fire-resistant and it does not absorb moisture.
It is lightweight, easy to install, not pricey, versatile, and it effectively reduces reverberation or
some other unwanted noise. It may be found in the form of a glass made of a large, rigid, and
fibrous board suitable for interior panels, ceiling panels, office partitions, appliances, furniture,
machine rooms.

B.Arch 5th
Acoustic Materials
Sound Diffusers
Sound diffusers are designed to scatter or disperse sound waves,
thereby reducing standing waves and echoes to improve sound
clarity. Diffusers (or Diffusors) are typically used in critical listening
environments like recording studios, control rooms, music
production and live music rooms.
Unlike sound absorbers that trap or eliminate the sound, sound
diffusers maintain the “live” ambience, while at the same time
reducing standing waves and slap echo. Diffusers may be
manufactured from molded plastic or Glass and may be wrapped
or covered in various fabrics.
Sound diffusers are often used in combination with other
materials such as sound absorbers, bass traps, ceiling clouds or
other provisions to achieve the desired results for the application.

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Acoustic Materials
Sound Diffusers-Types
There are two main types of acoustic diffuser, skyline and quadratic. They rely on similar
mathematical principles to diffuse sound. One uses wells or troughs; the other uses different
tower heights. They are basically the inverse of the other. Skyline diffusers take up more space
and are heavier than QDR diffusers.
Skyline Diffuser
Skyline diffusers use solid square cut blocks of calculated length
arranged in a set pattern to scatter sound waves evenly. The
pattern of the blocks makes it look like a city skyline.
Quadratic Residue Diffuser
A quadratic diffuser uses wells or troughs of calculated depths
and widths, also in a set pattern, to predictably control the
diffusion of soundwave in an even pattern.
Skyline Diffuser
Quadratic Diffuser

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Acoustic Materials
Noise Barriers
A noise barrier also called a soundwall, noise wall, sound berm, sound barrier, or acoustical
barrier is an exterior structure designed to protect inhabitants of sensitive land use areas
from noise pollution. Noise barriers are the most effective method of mitigating roadway,
railway, and industrial noise sources – other than cessation of the source activity or use of
source controls.

B.Arch 5th
Acoustic Materials
Sound Reflectors
Sound reflectors are acoustical materials used to reflect and concentrate waves of sounds to a
particular point. This property helps in amplifying sounds without the use of artificial amplifiers.
This is generally avoided in smaller spaces as concentration of sounds results in high intensity
sounds which are harmful. Gypsum boards, vinyl or fabric-finishes are commonly used reflective
materials.
Hard, reflective, nonporous interior building surfaces such as glass, wood, plaster, brick and
concrete absorb 2% to 5% of the sounds striking the surface to reflect 95% or more of
the sound. Absorption coefficients are expressed as a percentage of the sound absorbed.
Materials with smooth finish also acts as good sound reflectors.
Sound Waves are considered to be mainly consist of kinetic energy
when it collides with any of the surface it releases its kinetic energy in
the form of heat.
Smooth surface allow fewer oppurtunity of collisions between sound
wave and surface molecules, results in reflection of soundwaves

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Acoustic Materials
Acoustical Materials used in Building Components

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Acoustic Materials
Acoustical Treatment in Buildings
Sound treatment is a key design consideration for almost every building, regardless of industry,
in order to reduce noise disturbance and enhance sound quality. When noise is made within
your building, it will either be absorbed, reflected or transmitted by your wall, ceiling and
flooring.
The goal of sound treatment is twofold:
1. Prevent transmission of sound from room to room and floor to floor, and
2. Reduce background noise to enhance the quality of speech or music within rooms.
Acoustical Flooring
Installing acoustic flooring is an effective and efficient way of accomplishing the former goal.
While acoustic ceiling and wall treatments protect against transmission of sound from room to
room, acoustic flooring is effective at preventing the transmission of sound from an upper floor
to a lower floor. Together with ceiling and wall coverings, acoustic flooring system will help
create the best acoustic environment for building’s application

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Acoustic Materials
Flooring
Types of noise acoustic flooring can help with
In general, acoustic flooring must prevent the transmission of two types of noise:
Impact sound
Whether from foot traffic, carts or vibrating
machinery, floors bear the brunt of impact
within your building. The sound energy
generated by this impact can be transmitted
through the structure of your building,
distorting noise and disturbing workers, guests
or residents. Acoustic flooring is designed to
insulate impact noise, preventing its
transmission from your flooring into the rooms
below.

B.Arch 5th
Acoustic Materials
A flooring material’s effectiveness at preventing the transmission of impact noise is measured by
its impact insulation class (ICC). The higher a flooring’s ICC, the more impact sound insulation it
provides.
A material’s ICC rating is measured using a “hammer machine” on an upper floor, and measuring
the sound in decibels in the room below. Floating floors, carpet pads and sound-insulating
underlayment can greatly improve a flooring system’s ICC rating.
Flooring
Airborne sound
Airborne sound typically stems from people, speakers and instruments. Like impact sound,
airborne sound can transmit through your flooring into other parts of your building.
A material’s ability to prevent the transmittance of airborne sound is measured using a different
metric—sound transmission class (STC). An STC rating is a logarithmic measure of a sound’s
transmission loss between two rooms, measured across 16 frequencies from 125 Hz to 5000 Hz.
Essentially, a material’s STC rating measures its ability to absorb airborne noise and,
consequently, prevent its transmission.

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Acoustic Materials
Flooring-Solutions
Carpet
Carpet is known for mitigating impact sound, making it a perfect choice for hotels, classrooms
and offices. Higher pile carpets or carpets with a thick pad underneath, are especially good at
absorbing sound and reducing transmission.

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Acoustic Materials
Flooring-Solutions
Cork flooring
Cork flooring is a sustainable, comfortable and sound-absorbent flooring option perfect for many
commercial applications. Still, due to its tendency to stain and indent it is often used as an
underlay to provide acoustic insulation.

B.Arch 5th
Acoustic Materials
Flooring-Solutions
Wood Plastic Composite (WPC) flooring
Durable, waterproof and easy to maintain, WPC flooring provides great acoustic benefits,
especially when it comes to mitigating the impact noise such as high foot traffic. Its acoustic
benefits are largely drawn from its backing layer, which not only provides sound insulation, but
also protects against mold and mildew.

B.Arch 5th
Acoustic Materials
Flooring-Solutions
Rubber flooring
Commercial rubber flooring is known for its sound absorbent qualities. More than that, it is slip-,
mold- and mildew-resistant. It is a great choice for hospitals, schools, gyms and kitchens looking
for a durable acoustic flooring material.

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Acoustic Materials
Flooring-Solutions
Vinyl tile
Vinyl tile, especially luxury vinyl tile (LVT) installed with a sound-insulating underlayment, is a
great resilient flooring option used for sound treatment. It is selected by many facilities due to
its design versatility, durability and relatively low maintenance costs.

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Acoustic Materials
Walls- Acoustical Treatment
Acoustical Treatments on walls can be done by using materials listed as below:
1. Acoustical Foam Panels for Wall
2. Acoustical Fabric Panels for Walls
All of the above treatments are already described in this presentation above.

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Acoustic Materials
Roofs/Ceilings- Acoustical Treatment
Acoustic ceiling panels serve as barriers to block sound from travelling to adjacent rooms and
also as a means to reduce the noise within a room. As they soften, remove, and diffuse
sounds, acoustic panels help create a more pleasant environment, free of echoes and
bothersome noise
One type of suspended ceiling is made up of Acoustic Ceiling Tiles (ACT) and a stick-built grid
system. Sometimes called a lay-in ceiling, this type of system is versatile, durable, and cost
effective. In addition, the ceiling tiles can be removed without damage to the system so that
above ceiling items can be maintained. Seen throughout many commercial and institutional
buildings, ACT is a popular ceiling material that now has a wide variety of aesthetic options.

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Acoustic Materials
Suspended Acoustic Ceiling Components

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Acoustic Materials
Ceiling Grid T Shapes
Edge Moulding

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Acoustic Materials
Ceiling Grid T Shapes
Ceiling tiles come in an infinite variety of textures and designs. Most ceiling tiles are made from
mineral fiber, but other materials are available, such as fiberglass. Mineral fiber tiles typically
have a high Noise Reduction Coefficient (NRC), which means they are good at absorbing sound
within a space to prevent echo or loud environments. While some tiles have a high Ceiling
Attenuation Class (CAC), meaning they prevent sound from passing through the ceiling to
another space, acoustic ceiling tiles are generally not used to provide privacy between spaces.
In addition to tile material, there are a wide variety of designs available. Tiles may have a rough
appearance or a smooth appearance. Tiles may also have designs imprinted in them or other
patterns scored into the tile. There are a few edge options that are typical, as shown below.

Unit 3 Acoustic Materials.pptx.pdf

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