Sound in the learning environment BB93

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2 Sound in the learning environment Numerous studies have proven that noise in schools has a major effect on teaching and learning. Speech intelligibility research in the US indicates that pupils fail to hear every fourth word because of noise and reverberation in the classroom, whilst another study discovered that teachers form a disproportionate percentage of voice clinic patients due to the constant need to raise their voices. Nuisance noise in educational environments can arise from both internal and external sources. This can include the proximity of the building to a road or railway, impact sound generated from footfall and low frequency noise from ventilation systems. Consideration is also required for areas which have low noise tolerance levels, for example libraries and study rooms. To avoid disruption once the rooms are in use, the acoustic performance of these noise sensitive spaces should be preserved. BB93 To help improve the acoustic conditions within schools, a set of design standards, Building Bulletin 93 (BB93), came into force in To meet the regulations and recommendations, the three basic acoustic criteria that should be addressed are: reverberation times, sound absorption and sound insulation, whether between or within spaces. BB93 is a mandatory requirement for all new school developments and a design target for higher education and refurbishments. Governed by the Building Regulations, BB93 provides a guide for architects, building control bodies, building services, engineers, clients and others involved in the design of school buildings.

3 Summary of BB93 room-specific criteria The table below summarises the requirements for maximum indoor ambient levels, L Aeq, 30min (from building services and the environment outside the school premises), average reverberation time between 500Hz and 2kHz, T mf, and the maximum impact sound pressure level transmitted into a room, L nt(tmf,max),w. For sound insulation between rooms, the activity level and tolerance are given. If sound insulation between rooms of the same type is being considered, use the column headed minimum D nt(tmf,max),w between similar rooms in the table below. Type of room Activity noise (Source room) Noise tolerance (Receiving room) Upper limit for indoor ambient noise level, db L Aeq,30min Minimum D nt(tmf,max),w between similar rooms (db) Maximum impact sound pressure level L nt(tmf,max),w (db) T mf (seconds) Nursery school playrooms High Low < 0.6 Nursery school quiet rooms Low Low < 0.6 Primary school: classrooms, class bases, general teaching areas, small group rooms Average Low < 0.6 Secondary school: classrooms, general teaching areas, seminar rooms, tutorial rooms, language laboratories Average Low < 0.8 Open-plan Teaching areas Average Medium < 0.8 Resource areas Average Medium < 1.0 Music Music classroom Very high Low < 1.0 Small practice/group room Very high Very low Performance/recital room Very high Very low Recording studio Very high Very low Control room for recording High Low < 0.5 Lecture rooms Small (fewer than 50 people) Average Low < 0.8 Large (more than 50 people) Average Very low < 1.0 Classrooms designed specifically for use by hearing impaired pupils (including speech therapy rooms) Average Very low < 0.4 Study room (individual study, withdrawal, remedial work, teacher preparation) Low Low < 0.8 Libraries Quiet study areas Low Low < 1.0 Resource areas Average Medium < 1.0 Science laboratories Average Medium < 0.8 Drama studios High Very low < 1.0 Design and Technology Resistant materials, CADCAM areas High Very low < 1.0 Electronics/control, textiles, food, graphics, design/resource areas Average Medium < 0.8 Art rooms Average Medium < 0.8 Assembly halls, multi-purpose halls (drama, PE, audio-visual presentations, assembly, occasional music) High Low Audio-visual, video conference rooms Average Low < 0.8 Atria, circulation spaces used by pupils Average Medium < 1.5 Indoor sports hall High Medium < 1.5 Dance studio High Medium < 1.2 Gymnasium High Medium < 1.5 Swimming pool High High < 2.0 Interviewing/counselling/medical rooms Low Low < 0.8 Dining rooms High High < 1.0 Ancillary spaces (advisory levels) Kitchens High High < 1.5 Offices, staff rooms Average Medium < 1.0 Corridors, stairwells Average High High See separate table Coats and changing areas High High < 1.5 Toilets Average High < 1.5 Criteria for corridors, foyers & stairwells Method A Method B (applies to all frequencies between 250Hz and 4Hz) Corridors Stairwells Class D absorber to area equal to stair treads, upper Class C absorber to area of floor or greater surface of intermediate and top landings, or a Class C absorber to 50% of this area or greater Sum of surface area x absorption coefficient > 0.2m 2 for entrance halls and > 0.25m 2 for corridors, Not appropriate per cubic metre of volume

4 Controlling impact sound Impact sound can become an issue in schools incorporating more than one storey as it can penetrate the areas below. As such, attention must be given to the effects of footfall on areas such as stairs and those above corridors and classrooms. Acoustic underlays and underscreed isolation systems can be used to effectively control impact sound in these areas. Regupol 4515 range Regupol 7210C Comprising of Regupol 4515 Multi and Regupol 4515 Eco, the Regupol 4515 range of acoustic underlays offers a high performance solution of up to 23dB ΔL w to attenuate impact sound on all subfloors. Quick and easy to install, the Regupol 4515 range is suitable for use in new builds and refurbishments. Regupol 4515 Multi, a market leading system, is the only acoustic underlay to deliver acoustic performance with any floor finish. Manufactured from a polyurethane foam/cork compound, it offers long term and high quality performance without ageing or collapsing. Made from a rubber/cork compound, Regupol 4515 Eco offers a lower cost alternative to Regupol 4515 Multi, meeting BB93 requirements where hardwood and laminate floor finishes are being used. Quick and easy to install Offers long term performance without collapse or bottoming out under high point loads Resistant to ageing and deformation Reduces construction heights Suitable for use with any floor finish including ceramic/stone tiles Regupol 7210C is a cost effective rubber-bound underscreed product which is compatible with all types of floor screed. Quick and easy to install, it is simply fitted by turning up the material at the edges, with no need for separate perimeter strips. The material undergoes minimal creep and will not bottom out or collapse, even under high loading conditions. Resistant to ageing and deformation, Regupol 7210C is ideal for the educational environment as it provides impact sound insulation of up to 46dB L ntw. CMS Acoustics also offers Regupol E48, a recycled rubber crumb underscreed material, with a dimpled surface on one side for enhanced performance. Excellent impact and airborne acoustic performance Offers long term performance without collapse or bottoming out under high point loads Minimal creep, even under high loads Quick and easy to install. No need for separate perimeter strips Resistant to ageing and deformation Priory Community School Classrooms in a two-storey block at the new Priory Community School were situated directly above music rooms and an assembly hall. As such, the high noise levels generated from the music rooms and assembly hall needed to be attenuated. CMS Acoustics recommended and supplied Regupol 7210C, a high density rubber-bound underscreed isolation solution. Regupol 7210C minimised sound transfer between rooms at Priory Community School, ensuring that lessons remained undisturbed.

5 Absorbing sound CMS Acoustics offers a range of solutions, including acoustic wall coverings and bespoke panels, to directly absorb sound and reduce reverberation levels. The selection of the most appropriate system will depend on the application and environmental demands. Vertiface Composition SuperPhon Acoustic Wall Panels Adhering directly onto interior walls, Vertiface Composition is an attractive, high density polyester material that helps improve listening conditions by absorbing sound produced within a room and reducing the transmission of noise from outside. The level of reverberation reduction is dependent on the material thickness and the extent of coverage. Available in 12mm, 16mm or 22mm thicknesses, Vertiface Composition delivers a maximum noise reduction coefficient of 0.4 for 12mm material, assisting with compliance of BB93 guidelines. Class A sound absorption is achieved when 16mm or 22mm thicknesses are used in conjunction with battens. Non-toxic, non-irritant, recyclable and environmentally friendly material Offers a cushioned surface for impact protection Can be used as a pinboard Resistant to fading or staining Available in rolls or panels High flammability classification - BS476 parts 6 & 7 Class 1/Class 0 CMS SuperPhon interior panels are acoustically absorbent fabric covered panels of a composite construction. The panels reduce noise by impeding the transmission of sound through an element of the structure and by absorption of sound at the surface to achieve a noise absorption coefficient of up to When mounted on battens, CMS SuperPhon provides Class A sound absorption. The standard covering is an acoustically transparent woven textile fabric, however, bespoke panels of a specific size, thickness, shape or facing fabric can be manufactured upon request. This effective reverberation control can be achieved without changing the existing interior environment. High quality decorative finish Excellent acoustic and thermal insulation Flexible design characteristics Easy to handle, install, and clean Cost effective sound control High flammability classification - BS476 parts 6 & 7 Class 1/Class 0 Ryton Comprehensive To prevent the potential for damage from the impact of balls used in sports activity, a rendering system was installed on top of a sound absorbing layer in the new sports hall at Ryton Comprehensive, Tyne & Wear. As this inadvertently compromised acoustic performance, Gateshead Council had to source another treatment to minimise reverberation levels whilst protecting the wall surfaces within the sports hall. CMS Acoustics recommended Vertiface Composition to resolve these acoustic issues. As a result, 350m 2 of the chosen butter colour material was installed onto the upper half of the sports hall walls. Since installing Vertiface Composition, teachers and pupils at the school have been able to continue sports activity without suffering intolerable levels of reverberation. call

6 Reducing reverberation Treating ceilings is a common method of sound control in school environments as the products are placed out of the reach of pupils. This can be achieved using acoustic cladding or foam. Such products are intended for use in locations requiring extremely high levels of acoustic absorption, and can also make a significant contribution to the thermal resistance of buildings when incorporated into the roof construction. QuietStone Melamine Foam As a rigid, hardwearing cladding material, QuietStone provides an ideal reverberation solution for educational environments. Easily installed as both a wall and ceiling treatment, QuietStone controls noise levels by directly absorbing sound. With the appearance and texture of pumice stone, QuietStone offers an absorption coefficient of up to 1.08 when measured to BS3638 (Random Incidence Sound Absorption Coefficient), which is better than many soft materials. When installed correctly, QuietStone delivers sound insulation equivalent to a solid wall. Can be vacuumed, scrubbed and washed with detergents or even bacterio-cides without damage When used as a wall it will take fixings for shelves, speakers and lights etc As an acoustic ceiling solution it will fit into a standard suspended ceiling Excellent acoustic properties Class 0 fire rating CMS Melamine is a highly adaptable, fire resistant acoustic foam. Providing effective sound absorption, the acoustic performance can be enhanced further by maximising the surface area. Supplied as either panels or alternative designs, the lightweight foam is quick and easy to install, eliminating the need for highly engineered support mechanisms. CMS Melamine can be suspended from ceilings, applied directly to walls and shaped to individual requirements. A range of painted surfaces or fabric finishes are available to provide an aesthetically pleasing and improved listening environment. Available in panels, cubes or custom shapes Wide variety of colours and choice of finishes Lightweight, easy to handle and install Suitable for high temperature applications Fibre and dust free Available with self adhesive backing and Class O foil facing Autism.westmidlands The specialist environment of Autism.westmidlands school required background noise levels to be addressed, to avoid causing stress and anxiety for the autistic pupils. The dining hall was identified as a problem area as its concrete design intensified reverberation noise caused by metal knives and forks. To reduce reverberated noise in this area of the school, CMS Acoustics provided its Melamine foam with self adhesive backing. The 2.5m x 1.25m x 30mm thick sheets were easily installed on the entire 44m 2 of the dining hall ceiling. Since the installation of the acoustic foam, background and vocal noise has been reduced in the dining hall by up to 40 per cent and has ultimately helped to create a better environment for the pupils.

7 Controlling airborne sound High performance treatments for interior walls and ceilings can be used to control airborne sound in large spaces with high ceilings, such as music rehearsal rooms, assembly halls, gymnasiums and swimming pools. CMS Acoustics offers a broad selection of solutions to improve the acoustic quality of these spaces whilst providing an aesthetically pleasing finish. Kinetics Wave Baffles Kinetics Ovation Reflection Panels Kinetics Wave Baffles are a cost effective method for reducing reverberation times in large open spaces. Designed for horizontal suspension in a wave-like form at ceiling level, the baffles consist of a fibreglass blanket encapsulated in a sewn cloth fabric. Two types of wave baffle are available to improve acoustics and reduce noise in high cubic volume areas. The baffles have either a woven scrim backer (Type SE) or a heat sealed vinyl covering on both sides (Type HB). When face finished on each side, both types of wave baffles can be hung vertically as an acoustic banner. Produced in custom sizes Available in a variety of finishes Can be suspended as horizontal clouds or vertical baffles Grommet or suspension hardware is located at the perimeter as required Can be engineered to create the desired amount of vertical drop between suspension points Designed for use in large spaces requiring superior acoustics, Kinetics Ovation Reflector Panels have a bowed surface comprising a plywood core with a fibre reinforced gel coat. The panels can be positioned to direct sound to an audience in lecture halls, performing arts areas and music rehearsal rooms. Available in a range of colours and finishes to match the interior design, the curved panels can be ceiling suspended, wall mounted or built on a retractable frame, allowing horizontal to vertical orientation of the reflector. Position can be adjusted for optimal acoustic performance Choose from a range of finishes and colours Also available in laminate or hardwood veneer finishes on a plywood core board Custom sized to fit the space Can be mounted onto ceilings or walls John Madejski Academy Specialising in PE and sport, the John Madejski Academy required reverberation times to be reduced in the sports hall to improve the sound quality. However, high usage of the hall meant an acoustic solution had to be identified that would not be damaged by sports activities. As a result, CMS Acoustics recommended and supplied Kinetics Wave Baffles to absorb airborne sound. The high performance, curved acoustic panels were suspended from the ceiling in the sports hall and have effectively reduced reverberation times without compromising the space available for lessons. call

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