open plan teaching - mach acousticsmachacoustics.com/pdfs/reports/2-open-plan-teaching.pdf ·...

Presented by Ze Nunes of MACH Acoustics 25 Bishop Road, Bishopston, Bristol, BS7 8LS [email protected] mobile 07730590904

Open Plan Teaching

MACH ACOUSTICS

Introduction


This report presents MACH Acoustics approach to the acoustic design of Plazas 1 and 2 at Olborough School, Kent.

The aim of this report is to highlight MACH Acoustics innovativeapproach to both assessing the acoustic requirements and presenting the requirements of open plan teaching spaces.

MACH ACOUSTICS

Project ArchitectsSMC Alsops Plaza 1 Gernsler Plaza 2

Project Aims


The projects goal was to form open plan spaces promoting group work in a free and open space, such to enhance both learning andteaching. This project aims to move away from the cellular, individual working spaces within a conventional school as below, by providing an open learning environment for 60 to 90 pupils.

MACH ACOUSTICS

To Teachers

Promoting group activities rather than an individual in a cellular roomSignificantly improving the interaction between teachersAssists in the sharing of information and teaching skills between teachersAssists teachers in learning from one anotherPrevents people from hiding away within cellular spaces

To Pupils

Provides all the benefits above to pupils Dramatically enhances the pupils learning experienceProvides a flexible, desirable environment in which to work and learn within.


The Benefits of Open Plan TeachingMACH ACOUSTICS

Open Space

Create an open space, free from cellular classrooms. Removal of all screens and partitions, allowing users to see each other and work together. Provide a space capable of holding 60 to 90 pupils

Large Flexible Spaces

Create a space where teachers and pupils can move around, using a range of seating layouts, environments and learning tools.

Positive Comfortable Space

Provide a high level of comfort and flexibility and an atmosphere which appeals to a wide range of students. Create a building which provides a positive, forward thinking environment, rather than the standard Victorian teaching often found in schools.


Design Goals for Open Plan TeachingMACH ACOUSTICS


Images from Plaza 1 – A functional open spaceMACH ACOUSTICS

Stage 1 Acoustics of teaching spaces – Review the acoustic needs for different teaching spaces by means of acoustically assessing existing classrooms.

Stage 2 Review – Carry out an in-depth literature review.

Stage 3 Design solutions – Review design options such to improve the acoustics in open plan spaces.

Stage 4 Consultation – Consultation with the school, end users and the design team. Ensure that both the users requirement and acoustic design requirements are achieved within the completed building

Stage 4 BB93 – Such to comply with Building Regulations, undertake a full and detailed assessment using Ray tracing models and on site data. Present reports to Building Control.


MACH Acoustics Design ApproachMACH ACOUSTICS

This arrangement sees tables in a linear style within a cellular rectangle space. The teacher predominantly stands at the front providing information to all pupils.

When pupils work in groups, group sizes tend to be small due to the layout and orientation of tables.

Noise levels within these spaces are not seen to be particularly high. The main source of noise is the teacher talking and small groups of pupils.


Stage 1 - The Acoustics of ClassroomsMACH ACOUSTICS

The arrangement of these spaces promotes group work. Pupils typically face each other and work in larger groups.

Teachers in this case are seen to provide limited levels of information. This information is typically provided at the start of a lesson or off a white board.

Noise levels generated by pupils are high. This is due to the large number of people talking and the competition to be heard and understood within a noisy space. In summary, these areas are highly noisy.


Stage 1 - Island Tables – Labs/WorkshopsMACH ACOUSTICS

Pupils within the library at OldboroughSchool where working in groups, taking instruction from an interactive board.

The teacher was moving between pupils around the perimeter of this space, pupils where working in groups of 2-5 with only light separation between work stations.

Noise levels within this space where not seen to be particularly high. An experiment was conducted where the teacher spoke in a quiet voice and showed that due to the desk arrangement, pupils at the back of the class received an insufficient level of information.


Stage 1 - The Acoustics of Multi Use SpacesMACH ACOUSTICS

Classrooms - Understanding speech is key, this form of teaching is relatively quiet and it is seen that more than one teaching event can be conducted within a shared teaching space.

Island Tables – This is the noisiest type of teaching environment. This type of teaching should be avoided within open plan teaching. To reduce noise levels, island tables should be placed as far away as possible from each other.

Multi Use Spaces – These spaces function well. Noise levels are not excessive butthe levels of teacher supervision within this type of space tends to be higher than in a conventional teaching classrooms.

DVD and AV – Sound from DVD’s and AV equipment has a wider frequency characteristic and tends to be louder than the spoken voice. Either the whole Plaza is addressed by this noise source, or this type of event is minimised or carried out in a cellular space.


Stage 1 - SummaryMACH ACOUSTICS

N Charlton Smith• Reduction in occupancy levels / more area per pupil (c.f. open-plan office design)• Increased distances between noise producing areas• Increased use of absorbent surfaces in floors, ceilings and partitions (focusing on 1000 to 4000 Hertz absorption)• Isolation of very noisy areas e.g. music rooms, gymnasia, halls, etc• Reduction of noise intrusion from road traffic et al.

E Tate Harte• The open plan layout should be limited to three class bases or less. • The unoccupied and furnished classroom reverberation time, should not exceed 0.4 seconds. • Absorption should be provided to the entire ceiling and floor area in order to achieve the recommended reverberation time. • Activities should be co-ordinated as far as possible to avoid conflicting noise levels and conditions.


Stage 2 - Literature ReviewMACH ACOUSTICS

Layouts – the layout of the space will affect the distance between desks and potentially the snow balling effect of large groups contained within a small area.

Distance - Sound is reduced over distance. This has two consequences, firstly, teaching spaces placed further apart will benefit from increased levels of separation and b) teachers and pupils will over distance, struggle to hear each other.

Screens – breaking the line of sight between two points is often an effective way of providing a small but effective acoustic break between two spaces.

Partitions – when high levels of separation are required, partitions are seen to be the only solution

Soft Treatments – Soft treatments are required both to promote speech intelligibility but also to reduce the level of noise within the Plaza and reduce the spread of noise across these spaces.


Stage 3 - Acoustic Design SolutionsMACH ACOUSTICS

One of the key acoustic requirements for open plan spaces is to minimise interaction between small groups, such to control noise levels. It is important to prevent one group shouting across an open space to a second group.

The figure on the left therefore shows desk spaces with 5 students separated by larger tables of 15/30 students under supervision.

The figure over leaf provides a seating arrangement for Plaza 2. The coloured areas represent class bases. This arrangement of desks reduces the need to talk/shout over large distances and hence reduces the noise levels within an open plan space.


Stage 3 - Acoustic Design Solutions - LayoutsMACH ACOUSTICS

Breaking up teaching spaces and preventingthe build up of noise


Stage 3 Acoustic Design Solutions – Layouts • MACH ACOUSTICS

Seating arrangements within Plaza 2 – Aid to control noise build up

The layouts above show that it is possible to reduce the distance between the teacher and pupils by 1.25m if a horse shoe arrangement is used. Reducing the distance between teachers and pupils is fundamental to enhance speech intelligibility and reduce noise levels


MACH ACOUSTICS

Stage 3 - Design Solutions – Reducing Distances

An amphitheatre is a known method of increasing sound levels across an audience. By removing tables and using tablets it is possible to further reduce the distance between teacher and pupils.


MACH ACOUSTICS

Stage 3 - Design Solutions – Increasing Speech Levels

Based upon the above design principles, the Banana seat arrangement was derived. The distance between pupils and the teacher is only 2.6m, this design therefore significantly enhances speech intelligibility and reduces noise building up in open plan spaces.


MACH ACOUSTICS

Stage 3 - Design Solutions – Bananas

The Bananas

Speech Inteligbiliyt Measurments

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12

Poistions

STI V

alue

STI without BananasSTI with Bananas

BB93 Trarget Value

Banana Locations


MACH ACOUSTICS

Stage 3 - Design Solutions - Screening

The results of speech intelligibility testing within Plaza 1 are shown below. The diagram on the left shows the location of each assessment point. The graph indicates good speech intelligibility levels across the audience.

Due to the acoustic screening effects of the bananas, speech intelligibility levels drop off dramatically on the opposite side of the bananas. This is a desirable effect, meaning that the bananas in effect provide a teaching zone in which to work in.

It has been shown by S. Airey that occupancy noise levels are significantly reduced, by controlling the snow ball effect. This is achieved by increasing the levels of soft treatments in open plan spaces.

S. Airey indicated that a 9 dB reduction in occupancy noise can be achieved if a reverberation time of 0.4 seconds was used. MACH Acoustics therefore uses this design goal.


MACH ACOUSTICS

Stage 3 - Acoustic Design Solutions - Rt < 0.4 Seconds

One of the key design goals in open plan design is the removal of partitions and cellular spaces.

On the other hand, it is accepted that some spaces may need to be screened off to aid with the flexibility of the open plan teaching space.

For these spaces to be in keeping with design goals, they must be flexible and not allocated a specific task.

.


MACH ACOUSTICS

Stage 3 - Design Solutions - Partitions


MACH ACOUSTICSStage 3 - Audio Visual Enhancements

Teacher Wireless System SpeakersTraffic Light System

Audio Visual equipment bring advantages in that it is possible to create audio zones. Additionally, Audio Visual equipment can be used to monitor and indicate to users when noise levels are too high.

MACH ACOUSTICS


Speech spreads from one space to another as a result of teachers projecting their voices. Placing two speakers on either side of the teacher will only make matters worse.

A voice enhancement system can provide more localised sound meaning that the spread of noise is reduced. This system works by using large number of small speakers such to enhance the spoken voice.

Stage 3 - Voice Enhancement System


MACH ACOUSTICS

As noted above, Voice Enhancement systems work by propagating sound through multiple low power speakers. It is therefore possible to use a range of speaker systems.

Sound Bug this is a device attached to a table, which turns the table into a speaker.Bluetooth Speakers these speakers are highly portable delivering flexible, portable AV systems. Soft Speaker a portable system delivering a flexible, fun, AV system. Laptop the speakers within these units make an ideal VE system

Stage 3 - Voice Enhancement System

Sound Bug Bluetooth speaker Soft discreet LaptopHidden Speaker


MACH ACOUSTICSStage 3 - Traffic Light System – Detailed Modelling

MACH Acoustics have been working on a software tool enabling real time monitoring of noise levels within a teaching space. This system is aimed at changing the colour of lights on a desk, see Figure below.


MACH ACOUSTICS

Just Getting Tooright noisy noisy

Figure 3 Discreet LED providing teachers with an indication of their voice levels

Stage 3 - Indicators

Figure 1 Projectors change colour with noiseFigure 1 Light changes colour with noise

BB93 requires a background noise level of 35 dB(A) or less. This requirement is important and can be achieved by means of naturalventilation and simple openable windows.

BB93 requires Speech Intelligibility levels (STI) of 0.6 or greater.

BB93 requires a reverberation time of 0.8 seconds or less. For the reasons given above, this project requires a reverberation time of 0.4 seconds or less.

Imaginative and creative solutions must be proposed to over comesome of the clashes between acoustics open plan spaces.


MACH ACOUSTICS

Stage 5 - BB93 ‘Acoustics Design for Schools’

To demonstrate compliance with BB93, a full set of measurements have been undertaken within classrooms and Plaza 1 at Olborough school. This data has then been used within computer simulated models demonstrated compliance with BB93 requirements


MACH ACOUSTICS

Stage 5 - BB93 ‘Acoustics Design for Schools’

This report summarises MACH Acoustics approach to the design of open plan spaces.

From a series of site assessments post the occupation of this building, it has been shown that the acoustic principles used within the development of this building, provide a functional, flexible and exciting space to learn in.

On the success of Plaza 1, Plaza 2 is almost complete and the development of a complete academy is in progress.


MACH ACOUSTICS

Consolation

open plan teaching - mach acousticsmachacoustics.com/pdfs/reports/2-open-plan-teaching.pdf ·...

Documents