CEILING SYSTEMS

[ B e t w e e n u s , i d e a s b e c o m e r e a l i t y.T M

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ABLEA Bet ter Learn ing Env i ronment

Armstrong is renowned for its continued research anddevelopment into providing products that meet andexceed client needs and prides itself by consistentlydelivering innovative, sustainable, ‘Best Value’architectural solutions.

With investment in education experiencing the highestlevels in recent history, emphasis on deliveringexceptional multi-functional teaching & communityfacilities is becoming ever more demanding. Inproviding such facilities, considerable emphasis hasbeen placed on effective use. Recognising that teachingand learning are acoustically demanding activities; newguidelines have been published to ensure classroomintelligibility forms a basic requirement for any learningenvironment. After all, delivering a high standard ofeducation is all about good communication.

‘Education is the Government’s top priority’

Government figures project Capital investment to reachapproximately £10 billion over the next two years,promising a total investment of at least £15 billion by2007. In providing a programme of rebuilding &renewal, the Government has committed to ensuresignificant improvements within all primary & secondaryschools throughout England.

Of the 21,500 Government-maintained schools inEngland, notably 85% were built more than 25 yearsago and most, therefore, are reaching the end of theirdesign lives.

With new approaches to capital investment and anincreased number of new Government initiatives,Education is set to benefit from the guidelines andrecommendations of ‘Exemplar Designs’ – the DfEScompendium of exemplar designs for schools fit for the21st century.

Building Schools for the Future

As part of the recently published ‘Building Schools forthe Future’ (the Department for Education and Skillsconsultation on a new approach to capital investment),eleven of the country’s top architects headed designteams appointed to develop exemplar designs forprimary, secondary and all-through schools. Thedetailed ‘core’ brief required:

• Inspirational designs to stimulate both pupils and the school workforce;

• Flexibility to allow short-term teaching methods and the integration of ICT;

• Adaptability to suit long term changes in the size and number of rooms, and to provide a ‘kit-of-parts’that could suit a variety of sites and types of schools;

• Inclusive designs for those with SEN or disabilities

• Community use outside the school day;

• Safe secure and sustainable designs;

• Suitability of designs for some off-site construction;

• Excellent environmental design to at least meet standards of Building Bulletins (BB) 87 & 93.

Building Bulletin ‘93 (BB93)

Representing a significant tightening of the regulation ofacoustic design in schools and supported by researchshowing that teaching and learning are acousticallydemanding activities; BB93 provides a regulatoryframework for the acoustic design of schools in supportof the Building Regulations.

Whilst providing support and advice for planning anddesign of schools, ‘The overall objective of theperformance standards in Section1.1 (of BB93) is toprovide acoustic conditions in schools that…facilitateclear communication of speech between teacher andstudent…and do not interfere with study activities.’*

* BB93, Section 1 - Specification of Acoustic Performance

In response to BB93, Armstrong World Industries, theWorld's leading supplier of acoustic ceiling solutions,have developed an initiative to assist in meeting therequired performance standards for:

• indoor ambient noise levels

• absorption between spaces and corridors

• reverberation in teaching and study spaces

• speech intelligibility

The 'A.B.L.E.' initiative - 'A Better LearningEnvironment' - highlights Armstrong's market leadingrange of education specific acoustic ceilings products,emphasises our highly effective and innovative new i-ceilings Sound Field' solution (recommended inSection 6 of BB93) and offers educational, architectural& acoustic specifiers a complete package of advice,service and design assistance.

A Bet ter Learn ing Env i ronment

S o u n d F i e l d

Impact of Armstrong i-ceilings Sound Field toprovide a better learning environment:

It is accepted that good speech intelligibility is afundamental requirement when designing teachingenvironments. Whilst BB93 focuses on reverberationtime, consideration is given to the other basic elementsrequired to provide speech inteligibility.

Most students will be able to hear the teacher but notall can actually understand what is being said. Theability to communicate effectively within a classroom, orany space, depends on a few basic elements:

Appropriate reverberation time (RT)

Signal to Noise Ratio (SN)

Appropriate sound pressure level (SPL)

Combined at the optimum levels these elements willproduce a classroom that evolves into a communicationtool rather than a facility built to simply ‘meet-and-teach’.

- Speech Inteligibility (STI)

The speech transmission index is an objective measuredefined in BS EN 60268-16:1998, accountng for allvariables in room acoustics eg. room design, volumeand surface materials. The index provide a guide towhat RT is acceptable to create an effectivecommunication space.

- Reverberation time (RT)

The RT index is used to determine how quickly sounddecays in a room. The physical volume and surfacematerials used in the room dictate the RTcharacteristics.

Measured in time, high values represent more 'lively'resonating spaces - or increased 'echo'

Lower values indicated more dry spaces..

Classrooms environments are measures using theaverage value of RT from three specific octave bandscentered at frequencies of 500Hz, 1000Hz & 2000Hz.

- Loudness (SPL)

SPL is an indication of the loudness of a source (noise).eg, Normal speaking voice is about 60 dB(A) 120dB is the "threshold of feeling"130dB is artillery fire at 1 meter140dB (threshold of pain) is a jet aircraft at 5 meters- Signal to Noise (SN): Dynamic range

Signal to noise ratio measures the difference inloudness between ambient noise (background soundslike air conditioning, whirring of computer fans or evenexternal noise such as road or air traffic) and the signal(the speaker or person speaking). If the difference inloudness is too small, then background noise willdisrupt the intelligibility of the speaker.

The voice ‘s dynamic range is the difference betweenthe peak sound level and the peak background noise inthe space.

S o u n d F i e l d

Figure A. Typical Classroom

A typical classroom environment with aminimum level of sound absorption is clearlyexpressed as a lively space with excessiveloudness.

Figure B. Introducing passive control

Introducing passive control throughincreased levels of sound absorption will notaffect the voices’ dynamic range whereasoverall loudness has decreased – controllingRT and helping to deaden the space.

Figure C. Consider background noise

Background noise is often overlooked andcauses the most amount of disruption.Through external and internal noisepollution, background noise (blue line) hasbeen significantly increased detrimentallyaffecting the dynamic range – this willdestroy intelligibility.

Figure D. Introducing Active control

i-celings Sound Field system provides activeacoustic control to the classroom. Whenthe voice’s dynamic range is reinforced(sound field) the signal to (background)noise ratio is increased achieving optimumlevels of overall speech.

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Dynamic Range

Sound MeasurementAverage Level

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Times (s)

SPL (dBA)

SPL (dBA)

Times (s)

SPL (dBA)

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Dynamic Range Dynamic Range The Effect of Added Absorption

The Effect of Added Absorption

Sound MeasurementAverage Level

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Times (s)

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Dynamic Range

Sound MeasurementAverage Level

Background Level

Masking Level

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Dynamic Range

Sound MeasurementAverage Level

Background Noise Level

The brown spectrum features a standard human voice in a classroom environment.

The pale orange portion is the human voice’s dynamic range.

One of the simplest and most cost effective solutions is Sound Field - a voice reinforcement systems

designed to function in harmony with classroom acoustics and intelligibility.

I m p a c t

The impact of Armstrong's SoundField solutions...Being widely accepted as the largest single area usedto passively control room acoustics, Armstrong hasconducted extensive acoustical modeling to assess theimpact of global acoustic treatments, ceilings & i-ceilings, in learning environments.

How much ceiling absorption is required in yourdesign scheme?

Results featured (see graphs below), express that in atypical classroom, the i-ceilings sound reinforcementsystem enhances the room’s acoustical conditions byproducing more equal ‘loudness’ with overall increasedintelligibility. This configuration offers even levels oflistening conditions throughout the room as opposed toa ‘seat dependant’ situation where the back half of aclassroom may be penalised.

> Sound pressure levels (1000Hz) > Speech transmission index (STI) (average 500/1000/2000Hz)

Typical ClassroomTypical Classroom

Typical Classroom with i-ceilings

Typical Classroom with i-ceilingsTypical Classroom with i-ceilings

Uneven listening conditions

Uniform listening conditions

RaSTI

Total SPL [dB]

Total SPL [dB]

Max 65

Min 59

Max 67

Min 63Max. 0.75

Ear Level 1 Mtr

0.71

0.75

0.68

0.60

Ear Level 1 Mtr

Ear Level 1 Mtr

Good intelligibility

Excellent intelligibility

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0.71

0.72

0.73

0.64

0.65

65

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0.75 - 1.0

W a v e l l S c h o o lC l a s s r o o m s o f t h e F u t u r e

Challenging current thinking on school building design,‘Classrooms of the Future’ are providing and testing anew and dynamic vision of how schools should bedesigned in the future.

In response to collective ideas on what the majordesign drivers are likely to be, the focus is on creatinginnovative learning environments that are imaginativeand stimulating, with the aim of inspiring children toachieve more.

Wavell School is one of many to have harnessed bestpractice from this new initiative and produced it’s owninspiring learning space. Having all the latestdevelopments in ICT such as, Teleconferencing,Interactive Whiteboards and Sound Field voicereinforcement, the new futuristic classroom forms aflexible and adaptable teaching aid that can be used forboth school and the broader community.

With the ability to reorganise the space to the needs ofthe class or specific lesson, integrating Sound Field toimprove communication and intelligibility has removedhistoric restrictions of ‘fixed’ equipment that causesstatic design. Discreetly housing the i-ceilings SoundSystem, Armstrong’s Dune ceiling exactly matches i-ceilings and provides perfect placement for audioenabling the classroom to be used as intended -providing flexibility and practicality in both traditionaland dynamic classrooms.

With audio systems being used on the majority ofinteractive white boards to transmit multimedia, SoundField is simply integrated into the existing system usingwireless microphones and receivers.

B l a c k p o o l C i t y L e a r n i n g C e n t r e

As the UK's largest City Learning Centre, BlackpoolCLC required state-of-the-art conference facilities toreflect its distinguished status and ensure that thecentre would prove a real asset to the community.Videoconferencing, professional training andpresentation facilities, multiple projection screens,interactive whiteboards, integrated document camera,DVD, VCR and audio technology were all on the CLC's'wish list'.

Anticipating a wide range of users from schools andlibraries to businesses and local area forums, theintention was to install flexible teaching andpresentation facilities that could be adapted to suit theuser's requirements. Furthermore, as a pioneeringfacility in the community, aesthetics was a keyconsideration throughout the Centre.

With a fully integrated multimedia Audio Visua suite atthe heart of the conference facility, in keeping with theCentre's inspirational design, intended to simulate bothpupils and teachers alike, i-ceilings Sound Systemswere chosen to ensure the highest quality soundreproduction of clear intelligible voice and music.

Armstrong Dune Supreme was utilised throughoutproviding a modern, definitive ceiling system thatcontrols room acoustics.

S t . H e l e n A u c k l a n d P r i m a r y S c h o o l & N u r s e r y

Having recently completed a much-needed renovationof the school hall, teachers started to question thedesign. There was a problem with the acoustics.

Being one of the most frequently used spaces in theschool (for assembly, lunch, sports and variouslessons), the initial specification was to provide a bright,new and dynamic space to benefit teachers andstudents alike.

However, this was not the case. In practice, the roomdelivered poor acoustics and was difficult for teachersto use and for the students to understand. As amultipurpose space the design had to reflect the vastamount of activities that the space is used for and, as aresult, suffered from compromise. The walls, floor,windows and ceiling were all hard imperforate surfacesoffering little or no sound absorption creating a highlyreverberant environment. In practice this was verydisruptive effecting intelligibility and children could notunderstand what was being said.

Armstrong was asked to provide a solution, whicharrived in the form of Optima Board – a highlyabsorptive ceiling system replacing the existing paintedplasterboard ceiling. Combined with i-ceilings SoundField systems the reverberation time has beensignificantly reduced and the level of intelligibility hasdramatically increased providing a practical andfunctional facility.