Improving the acoustic environment of schools for pupils and teachers

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Improving the acoustic environment of schools for
pupils and teachers

• Bridget Shield Anne Carey
• London South Bank University
• Julie Dockrell Kate Rigby
• Institute of Education, University of London

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Outline of talk

• Acoustic requirements for classrooms
• Background to EPSRC project - previous research
• EPSRC project - aims and methodology
• Acoustic surveys of classrooms
• Remedial acoustic treatments to classrooms
• Teachers voice levels
• Amplification in the classroom
• installation
• benefits
• Summary and conclusions

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Acoustic requirements for classrooms

• To provide good listening and speaking conditions
  a classroom must have
• Low background noise
• Short reverberation time
• Good sound insulation
• between classrooms to minimise transmission of
  classroom noise
• of external façade to minimise intrusion of
  external noise

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Building Bulletin 93 (DfES, 2003)Acoustic design
of schools

• School buildings built since 2003 must comply
  with the Building Regulations
• Legal requirements for acoustic design of new
  schools specified in Section 1 of Building
  Bulletin 93

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Building Bulletin 93 (DfES, 2003)Acoustic design
of schools

• Indoor ambient noise levels
• Airborne sound insulation
• Impact sound insulation
• Reverberation time
• Sound absorption in corridors and stairwells
• Speech intelligibility in open plan spaces

DfES kept informed of results of EPSRC project
which will inform any revision of BB 93
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Two major research projects on classroom
acoustics

• The effects of noise on the attainments and
  cognitive performance of primary school children
• Department of Health/DEFRA 1999-2001
• Acoustic design guidelines and teacher strategies
  for optimising learning conditions in classrooms
  for hearing and hearing-impaired children
• EPSRC (EQUAL) 2002 - 2005

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Background - previous study
Methodology

• Noise surveys outside 142 primary schools in 3
  London boroughs
• Noise surveys inside 140 classrooms in 16 schools
  in two boroughs
• Questionnaire survey of all Year 2 children in
  one borough (Ngt2000) and their teachers (Ngt50)
• Comparison of noise levels with SATs results
• Experimental testing of mainstream and SEN
  children in typical noise conditions

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Background - previous study results

• Children are exposed to higher noise levels at
  school than recommended by BB 93 and WHO
• Children are aware of noise and annoyed by
  specific noise sources
• Ease of listening in the classroom is related to
  external noise levels
• Exposure to noise affected performance on
  academic tasks
• Classroom babble affects performance on verbal
  tasks
• External environmental noise affects non-verbal
  tasks and speed of processing tasks
• Children with special educational needs are
  differentially affected
• Majority of teachers experience voice and throat
  problems

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Effects of noise on Key Stage 2 SATs

• External noise (142 schools)

• Internal noise (16 schools)

Results hold when data corrected for
socio-economic factors
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Effects of noise on speed processing task
Changes in test scores in noise
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Effects of noise on children with special
educational needs
Results of experimental testing
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Acoustic design guidelines and teacher strategies
for optimising learning conditions in classrooms
for hearing and hearing-impaired children
Aims of EPSRC EQUAL project

• To identify those acoustic parameters that are
  most applicable to childrens hearing and
  listening in classrooms

• To investigate ways of improving the acoustics in
  classrooms

• To investigate the use and effectiveness of
  classroom amplification systems
• To investigate the effects of acoustics on
  teachers voices
• To develop new word tests for hearing and hearing
  impaired children

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Acoustic design guidelines and teacher strategies
for optimising learning conditions in classrooms
for hearing and hearing-impaired children
Aims of EPSRC EQUAL project

• To identify those acoustic parameters that are
  most applicable to childrens hearing and
  listening in classrooms

• To investigate ways of improving the acoustics in
  classrooms

• To investigate the use and effectiveness of
  classroom amplification systems
• To investigate the effects of acoustics on
  teachers voices
• To develop new word tests for hearing and hearing
  impaired children

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Acoustic design guidelines and teacher strategies
for optimising learning conditions in classrooms
for hearing and hearing-impaired children
Methods used in EPSRC EQUAL project

• 39 mainstream and special schools in London,
  Herts, Berks, Hants

• Acoustic surveys of 55 classrooms in 25 schools

• Measurements of voice levels of 36 teachers
• Study of installation and use of amplification
  systems (SFS) in 20 schools
• Questionnaire surveys of children with and
  without SFS
• Cognitive testing of children with and without
  SFS
• Structured observation of children with and
  without SFS

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Acoustic survey of 55 classrooms reverberation
times
18 out of 44 untreated rooms meet BB 93
criterion All treated rooms meet criterion
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Teachers voice levels
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What can be done to improve the acoustic
conditions for teaching and learning?

• For teachers
• For children
• mainstream
• with permanent hearing loss
• with temporary hearing loss
• with language problems
• with attention difficulties

• Two approaches investigated
• Increasing acoustic absorption to reduce
  reverberation time
• Using amplification/sound field systems in the
  classroom

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Effectiveness of acoustic treatment
Acoustic absorption can be added to the ceiling
(as here) or to the ceiling and walls
No absorption RT 1s
With absorption RT 0.5s
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Effectiveness of acoustic treatment
Measurements in 7 untreated and 6 matched treated
classrooms
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What is a Sound Field System (SFS)?
Amplification in the classroom

• A SFS is essentially a simple speech
  reinforcement system used by the teacher.
• Three main types - 4 small moving coil
  loudspeaker - single column loudspeaker -
  multiple flat panel (DML) in ceiling
• Systems usually consist of boom or collar mounted
  directional radio mic transmitter, radio mic
  receiver, mixer/amp loudspeakers.
• Typical price 1000 - 1500 per system.

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Why are SFS installed?
Amplification in the classroom

• To provide all pupils in the classroom with equal
  speech signal from the teacher
• Installed in classrooms where there is a hearing
  impaired child
• Installed for use by a teacher with voice
  problems
• Systems are installed for individual pupils, to
  improve acoustics by the school, or in a blanket
  manner by LEA.
• General misconception that SFS solve all
  acoustical problems

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Where are SFS installed?
Amplification in the classroom
SFS installed across whole range of classrooms
measured
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Amplification in the classroom
SFS were not used in about half of the classrooms
in which they were installed
Sound field systems can only be used successfully
if

• Acoustic conditions in the classroom are suitable
• They are installed correctly, in appropriate
  places in the classroom
• They are installed in consultation with the
  teachers who will be using them
• Teachers are given training in their use
• If they work!

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Examples of poor installation/communication
The loudspeakers have been installed in areas
where class teaching does not take place
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Example of poor training of the teacher
The loudspeakers have been decorated for
Christmas!

• Of teachers surveyed
• 56 not given any training in use
• of systems
• 63 not consulted about placing
• of systems

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Evaluation of sound field systems

• Schools in Hertfordshire and London
• Effects on childrens listening
• questionnaire survey of children in mainstream
  (Nq1396) and special schools (Nq128) before and
  6 months after installation
• Effects on childrens behaviour
• Structured observation of pairs of hearing and
  hearing impaired children in 9 classrooms with
  and without SFS
• Effect on childrens performance - SFS on/off
• testing of 380 children (24 with SEN) over 3 week
  period
• spelling, oral comprehension, speed of processing
• Effect on childrens learning - 6 months after
  installation
• testing of 280 children (41 with SEN) before and
  after
• spelling, oral comprehension, speed of
  processing, reading, maths

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Evaluation of sound field systems - impact on
listening

• Children in SFS classrooms reported improvements
  in hearing teacher in 3 out of 8 situations when
  teacher is speaking
• writing on board
• working in groups
• children making noise outside classroom
• No changes for hearing impaired children
• small sample and possible technical difficulties
• Children in special schools reported improvements
  when
• cannot see teachers face
• writing on board
• moving around classroom
• children making noise outside classroom

Benefits in hearing teacher for majority of
children
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Evaluation of sound field systems - observational
results

• No changes between classrooms with and without
  SFS in
• adult involvement
• type of task performed by children
• type of sound made by children
• underlying teaching and learning activities
• In SFS classrooms
• children's hands raised less often
• children more attentive
• children respond more quickly to teacher
• children less distracted by external noise

Beneficial effects for all children
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Evaluation of sound field systems - effect on
childrens performance and learning

• Performance (SFS on/off)
• Improvements in spelling for all children
• no change in comprehension and speed of
  processing
• Improvements in spelling and comprehension for
  SEN children
• no change for speed of processing
• Effects greater for SEN children

• Learning (changes after 6 months)
• No changes in spelling and maths
• Significant improvements in comprehension and
  speed of processing

Improvement in processing oral input,
particularly for children with additional
learning needs
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Summary and conclusions

• The acoustic conditions in the majority of
  existing classrooms do not meet current
  regulations
• Reducing noise and reverberation would benefit
  childrens learning and teachers health
• Acoustic treatments can be applied to remedy the
  situation
• Amplification in the classroom can improve the
  listening and learning situation for mainstream
  children and those with additional learning needs
• Amplification is not a remedy for poor acoustics
• In order to be used successfully amplification
  must be installed
• in classrooms which are acoustically suitable
• in appropriate positions in the classroom
• in consultation with the teacher
• with adequate training of teachers

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Current and further EPSRC research

• The acoustics of open plan classrooms
• (LSBU, EPSRC studentship, 2003 - 2007)
• Modelling performance of SFS
• (LSBU, EPSRC studentship, 2005 - 2008)
• The acoustic design of secondary schools
• (LSBU, IoEd, Univ of Salford, new application)

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Help needed

• Access to schools
• Opportunities to do before and after testing
  (acoustic and psychological) where remedial
  treatment/structural alterations planned
• Access to classrooms to test new word test

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Acknowledgements
This work has been funded by the Engineering and
Physical Sciences Research Council.
Contacts
Julie Dockrell j.dockrell_at_ioe.ac.uk Bridget
Shield shieldbm_at_lsbu.ac.uk