Architectural acoustics
Encyclopedia
Architectural acoustics is the science of noise control
within buildings. The first application of architectural acoustics was in the design of opera houses and then concert halls. More widely, noise suppression is critical in the design of multi-unit dwellings and business premises that generate significant noise, including music venues like bars. The more mundane design of workplaces has implications for noise health effects
. Architectural acoustics includes room acoustics
, the design of recording and broadcast studios, home theaters, and listening rooms for media playback.
, wall
s, window
s, door
and penetrations. Sufficient control ensures space functionality and is often required based on building use and local municipal codes. An example would be providing a suitable design for a home which is to be constructed close to a high volume roadway, or under the flight path of a major airport, or of the airport itself.
panels (such as wood dropped ceiling
panels), door
s, window
s, flanking, ducting
and other penetrations. An example would be providing suitable party wall
design in an apartment complex to minimise the mutual disturbance due to noise by residents in adjacent apartments.
of controlling a room's surface
s based on sound absorbing and reflecting properties. Excessive reverberation time, which can be calculated, can lead to poor speech intelligibility.
Sound reflections create standing waves that produce natural resonances that can be heard as a pleasant sensation or an annoying one. Reflective surfaces can be angled and coordinated to provide good coverage of sound for a listener in a concert hall or music recital space. To illustrate this concept consider the difference between a modern large office meeting room or lecture theater and a traditional classroom
with all hard surfaces.
Interior building surfaces can be constructed of many different materials and finishes. Ideal acoustical panels are those without a face or finish material that interferes with the acoustical infill or substrate. Fabric
covered panels are one way to heighten acoustical absorption. Finish material is used to cover over the acoustical substrate. Mineral fiber board, or Micore, is a commonly used acoustical substrate. Finish materials often consist of fabric, wood or acoustical tile. Fabric can be wrapped around substrates to create what is referred to as a "pre-fabricated panel" and often provides good noise absorption if laid onto a wall. Prefabricated panels are limited to the size of the substrate ranging from 2 by 4 ft (0.6096 by 1.2 m) to 4 by 10 ft (1.2 by 3 m). Fabric retained in a wall-mounted perimeter track system, is referred to as "on-site acoustical wall panels". This is constructed by framing the perimeter track into shape, infilling the acoustical substrate and then stretching and tucking the fabric into the perimeter frame system. On-site wall panels can be constructed to accommodate door frames, baseboard, or any other intrusion. Large panels (generally, greater than 50 square feet (4.6 m²)) can be created on walls and ceiling
s with this method. Wood finishes can consist of punched or routed slots and provide a natural look to the interior space, although acoustical absorption may not be great.
There are three ways to improve workplace acoustics and solve workplace sound problems – the ABCs.
While all three of these are recommended to achieve optimal results, C = Cover-up by increasing background sound produces the most dramatic improvement in speech privacy – with the least disruption and typically the lowest cost.
Inadequate control may lead to elevated sound levels within the space which can be annoying and reduce speech intelligibility. Typical improvements are vibration isolation
of mechanical equipment, and sound traps in ductwork. Sound masking
can also be created by adjusting HVAC noise to a predetermined level.
Noise control
Noise control is an active or passive means of reducing sound emissions, often incentivised by personal comfort, environmental considerations or legal compliance. Practical and efficient noise control is wholly reliant on an accurate diagnosis of what is causing the noise, which first involves...
within buildings. The first application of architectural acoustics was in the design of opera houses and then concert halls. More widely, noise suppression is critical in the design of multi-unit dwellings and business premises that generate significant noise, including music venues like bars. The more mundane design of workplaces has implications for noise health effects
Noise health effects
Noise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance and sleep disturbance. Changes in the immune system and birth defects have been attributed to noise exposure...
. Architectural acoustics includes room acoustics
Room acoustics
Room acoustics describes how sound behaves in an enclosed space.The way that sound behaves in a room can be broken up into roughly four different frequency zones:...
, the design of recording and broadcast studios, home theaters, and listening rooms for media playback.
Building skin envelope
This science analyzes noise transmission from building exterior envelope to interior and vice versa. The main noise paths are roofs, eavesEaves
The eaves of a roof are its lower edges. They usually project beyond the walls of the building to carry rain water away.-Etymology:"Eaves" is derived from Old English and is both the singular and plural form of the word.- Function :...
, wall
Wall
A wall is a usually solid structure that defines and sometimes protects an area. Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air...
s, window
Window
A window is a transparent or translucent opening in a wall or door that allows the passage of light and, if not closed or sealed, air and sound. Windows are usually glazed or covered in some other transparent or translucent material like float glass. Windows are held in place by frames, which...
s, door
Door
A door is a movable structure used to open and close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates inside of a space....
and penetrations. Sufficient control ensures space functionality and is often required based on building use and local municipal codes. An example would be providing a suitable design for a home which is to be constructed close to a high volume roadway, or under the flight path of a major airport, or of the airport itself.
Inter-space noise control
The science of limiting and/or controlling noise transmission from one building space to another to ensure space functionality and speech privacy. The typical sound paths are room partitions, acoustic ceilingCeiling
A ceiling is an overhead interior surface that covers the upper limit of a room. It is generally not a structural element, but a finished surface concealing the underside of the floor or roof structure above....
panels (such as wood dropped ceiling
Dropped ceiling
A dropped ceiling is a secondary ceiling, hung below the main ceiling. They may also be referred to as a drop ceiling, false ceiling, or suspended ceiling, and are a staple of modern construction and architecture. The area above the dropped ceiling is called the plenum space, as it is sometimes...
panels), door
Door
A door is a movable structure used to open and close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates inside of a space....
s, window
Window
A window is a transparent or translucent opening in a wall or door that allows the passage of light and, if not closed or sealed, air and sound. Windows are usually glazed or covered in some other transparent or translucent material like float glass. Windows are held in place by frames, which...
s, flanking, ducting
Duct (HVAC)
Ducts are used in heating, ventilation, and air conditioning to deliver and remove air. These needed airflows include, for example, supply air, return air, and exhaust air. Ducts also deliver, most commonly as part of the supply air, ventilation air...
and other penetrations. An example would be providing suitable party wall
Party wall
Party wall is a dividing partition between two adjoining buildings that is shared by the tenants of each residence or business. The wall is sometimes constructed over the center of the property line dividing two terraced flats or row houses so that one half of the wall is on each property...
design in an apartment complex to minimise the mutual disturbance due to noise by residents in adjacent apartments.
Interior space acoustics
This is the scienceScience
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
of controlling a room's surface
Surface
In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...
s based on sound absorbing and reflecting properties. Excessive reverberation time, which can be calculated, can lead to poor speech intelligibility.
Sound reflections create standing waves that produce natural resonances that can be heard as a pleasant sensation or an annoying one. Reflective surfaces can be angled and coordinated to provide good coverage of sound for a listener in a concert hall or music recital space. To illustrate this concept consider the difference between a modern large office meeting room or lecture theater and a traditional classroom
Classroom
A classroom is a room in which teaching or learning activities can take place. Classrooms are found in educational institutions of all kinds, including public and private schools, corporations, and religious and humanitarian organizations...
with all hard surfaces.
Interior building surfaces can be constructed of many different materials and finishes. Ideal acoustical panels are those without a face or finish material that interferes with the acoustical infill or substrate. Fabric
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...
covered panels are one way to heighten acoustical absorption. Finish material is used to cover over the acoustical substrate. Mineral fiber board, or Micore, is a commonly used acoustical substrate. Finish materials often consist of fabric, wood or acoustical tile. Fabric can be wrapped around substrates to create what is referred to as a "pre-fabricated panel" and often provides good noise absorption if laid onto a wall. Prefabricated panels are limited to the size of the substrate ranging from 2 by 4 ft (0.6096 by 1.2 m) to 4 by 10 ft (1.2 by 3 m). Fabric retained in a wall-mounted perimeter track system, is referred to as "on-site acoustical wall panels". This is constructed by framing the perimeter track into shape, infilling the acoustical substrate and then stretching and tucking the fabric into the perimeter frame system. On-site wall panels can be constructed to accommodate door frames, baseboard, or any other intrusion. Large panels (generally, greater than 50 square feet (4.6 m²)) can be created on walls and ceiling
Ceiling
A ceiling is an overhead interior surface that covers the upper limit of a room. It is generally not a structural element, but a finished surface concealing the underside of the floor or roof structure above....
s with this method. Wood finishes can consist of punched or routed slots and provide a natural look to the interior space, although acoustical absorption may not be great.
There are three ways to improve workplace acoustics and solve workplace sound problems – the ABCs.
- A = Absorb {via drapes, carpets, ceiling tiles, etc.)
- B = Block (via panels, walls, floors, ceilings and layout)
- C = Cover-up (via sound masking)
While all three of these are recommended to achieve optimal results, C = Cover-up by increasing background sound produces the most dramatic improvement in speech privacy – with the least disruption and typically the lowest cost.
Mechanical equipment noise
Building services noise control is the science of controlling noise produced by:- ACMV (air conditioning and mechanical ventilation) systems in buildings, termed HVACHVACHVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...
in North AmericaNorth AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas... - ElevatorElevatorAn elevator is a type of vertical transport equipment that efficiently moves people or goods between floors of a building, vessel or other structures...
s - Electrical generatorElectrical generatorIn electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
s positioned within or attached to a building - Any other building service infrastructure component that emits sound.
Inadequate control may lead to elevated sound levels within the space which can be annoying and reduce speech intelligibility. Typical improvements are vibration isolation
Vibration isolation
Vibration isolation is the process of isolating an object, such as a piece of equipment, from the source of vibrations.-Passive isolation:Passive vibration isolation systems consist essentially of a mass, spring and damper ....
of mechanical equipment, and sound traps in ductwork. Sound masking
Sound masking
Sound masking is the addition of natural or artificial sound into an environment to cover up unwanted sound by using auditory masking. This is in contrast to the technique of active noise control...
can also be created by adjusting HVAC noise to a predetermined level.
See also
- Acoustic transmissionAcoustic transmissionAcoustic transmission in building design refers to a number of processes by which sound can be transferred from one part of a building to another...
- Noise health effectsNoise health effectsNoise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance and sleep disturbance. Changes in the immune system and birth defects have been attributed to noise exposure...
- Noise mitigationNoise mitigationNoise mitigation is a set of strategies to reduce noise pollution. The main areas of noise mitigation or abatement are: transportation noise control, architectural design, and occupational noise control...
- Noise Reduction CoefficientNoise Reduction CoefficientThe noise reduction coefficient is a scalar representation of the amount of sound energy absorbed upon striking a particular surface...
- Noise regulationNoise regulationNoise regulation includes statutes or guidelines relating to sound transmission established by national, state or provincial and municipal levels of government. After the watershed passage of the United States Noise Control Act of 1972, other local and state governments passed further regulations...
- Noise, vibration, and harshnessNoise, Vibration, and HarshnessNoise, vibration, and harshness , also known as noise and vibration , is the study and modification of the noise and vibration characteristics of vehicles, particularly cars and trucks...
- Room acousticsRoom acousticsRoom acoustics describes how sound behaves in an enclosed space.The way that sound behaves in a room can be broken up into roughly four different frequency zones:...
- Sound transmission classSound transmission classSound Transmission Class is an integer rating of how well a building partition attenuates airborne sound. In the USA, it is widely used to rate interior partitions, ceilings/floors, doors, windows and exterior wall configurations . Outside the USA, the Sound Reduction Index ISO standard is used...
- Wallace Clement SabineWallace Clement SabineWallace Clement Sabine was an American physicist who founded the field of architectural acoustics. He graduated from Ohio State University in 1886 at the age of 18 before joining Harvard University for graduate study and remaining as a faculty member...
External links
- Acoustical Society of America
- American Institute of Architects
- National Council of Acoustical Consultants
- Institute of Acoustics
- Speech Privacy Calculator
- diracdelta.co.uk Room mode calculator
- Optimum sizes for small rooms
- Aural Architecture
- WikiRecording's Guide to Recording Studio Acoustics
- Acoustic Modelling using Google SketchUp
- Concert Hall Acoustics
- Concert Hall Acoustics
- Everything You Always Wanted to Know About Concert Hall Acoustics
- An on-line version of an exhibition on concert hall acoustics originally shown at the South Bank Centre, London