Architectural acoustics 1028926 224753752 2008-07-10T07:47:16Z 85.177.84.38 {{Unreferenced|date=November 2007}} '''Architectural acoustics''' is the science of controlling sound within buildings. The first application of architectural acoustics was in the design of [[opera houses]] and then [[concert hall]]s. 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 [[workplace]]s 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. ==Building skin envelope== This science analyzes noise transmission from building exterior envelope to interior and vice versa. The main noise paths are [[roofs]], [[eaves]], [[walls]], [[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. ==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 [[ceiling]] panels (such as wood [[dropped ceiling]] panels), [[door]]s, [[window]]s, [[flank]]ing, [[Duct (HVAC)|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. ==Interior space acoustics== This is the [[science]] 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 produces natural resonances that can be heard as a pleasant sensation or an annoying one. <ref>"Handbook for Sound Engineers"Glen Ballou, Howards Sams Editors, page 56.</ref> In order to obtain a good audio quality it is used the Oscar Bonello criteria of modal density <ref>"A NEW CRITERION FOR THE DISTRIBUTION OF NORMAL ROOM MODES" - Journal of the Audio Engineering Society (USA) Vol. 29, Nro. 9 - September/1981. Oscar Bonello</ref> More information at [[Room acoustics]] [http://www.whyverne.co.uk/acoustics/Pages/cismslow/cism.htm ]. 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. [[textile|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 the good noise absorption if laid onto a wall. Prefabricated panels are limited to the size of the substrate ranging from 2'x 4' to 4' x 10'. 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) 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 ABC’s. A = Absorb (usually via ceiling tile) B = Block (via workstation panels, wall placement and workspace layout) C = Cover-up (via electronic 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 [[HVAC]] in [[North America]] * [[Elevator]]s * [[Electrical generator]]s positioned within or attached to a building * Any other building service infrastructure component that emits sound. Inadequate control may lead to elevated [[sound level]]s 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. ==See also == * [[Noise health effects]] * [[Noise mitigation]] * [[Noise Reduction Coefficient]] * [[Noise regulation]] * [[Acoustic transmission]] * [[Room acoustics]] ==External links== *[http://asa.aip.org/ Acoustical Society of America] *[http://www.aia.org/ American Institute of Architects] *[http://www.ncac.com/ National Council of Acoustical Consultants] *[http://www.ioa.org.uk/ Institute of Acoustics] *[http://www.cambridgesoundmanagement.com/speechprivacycalculator/index.aspx/ Speech Privacy Calculator] *[http://www.diracdelta.co.uk/science/source/r/o/room%20modes/source.html diracdelta.co.uk] room mode calculator. *[http://www.acoustics.salford.ac.uk/acoustics_world/concert_hall_acoustics/index.html An on-line version of an exhibition on concert hall acoustics originally shown at the South Bank Centre, London] *[http://www.SpacesSpeak.com Aural Architecture] *[http://www.wikirecording.org/Studio_Acoustics WikiRecording's Guide to Recording Studio Acoustics] *[http://www.rahe-kraft.de/cms/software.en.htm Acoustic Modelling using Google SketchUp] [[Category:Acoustics]] [[Category:Building engineering]] [[Category:Building defects|Acoustic problems]] [[de:Raumakustik]] [[es:Acústica arquitectónica]] [[fr:Acoustique architecturale]] [[id:Akustik ruang]] [[it:Acustica architettonica]] [[no:Bygningsakustikk]] [[sv:Byggnadsakustik]] [[zh:建筑声学]] ==References== {{reflist|2}}