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EAIS 2011 main lecture hall - photo by Martin Arvebro
The EIAS 2011 was a unique acoustics event held in Båstad in the south of Sweden. It was attended by around 160 people, mostly acousticians from around the world.
The feedback from the event was very positive and here is a brief glimpse of the EIAS 2011 event in a slide show.
Ecophon would like to thank all the speakers and delegates who participated and we look forward to the next one!
Workshops:
Auralisation
Sustainability and acoustics
Healthcare premises
Open plan offices
Educational spaces
Peter Rogers (Cole Jarman) - photo by Martin Arvebro
EIAS 2011 Workshop: Acoustics, sustainability and green buildings
Sustainability has become an underpinning principle of living. Sustainability does not only relate to recycling of materials and reduction of emissions but also acoustic quality matters. In this work shop we wanted to highlight the sustainability especially in relation to acoustics, and what role acoustics can play connected to green building certifications or ratings.
Presenters were René Gamba, Peter Rogers, Carsten Svensson and Jonas Skeppås.
Workshop: Acoustics, sustainability and green buildings
Moderator – Peter Rogers
Co-moderator – Carsten Svensson
René Gamba, GAMBA Acoustique et Associés, France
Acoustic comfort: A unique indicator of the quality of sound climate
In France, “HQE” proposes a methodology to design, build and exploit healthy and comfortable “green” buildings. To be certified "HQE" you have to match 14 targets, one of these is exclusively about acoustics, and acoustics meets also several other targets.
More than 3 targets have to be upper a very good level (and energy is one of these targets), more than 4 targets have to be above than a good level, and the other need to reach a basic level.
For each target (energy, waste, water, acoustics, etc) it is natural to try to express the performance, or the quality, by means of unique indicators easy to read and to understand. That is why the “GIAc” works to the definition of a unique indicator of the acoustic comfort in a place. The objective is to be able to post a label at the entrance of the building, with green arrows (it is very good), yellow (it is just good) orange (it is inferior), red (it is bad), or purple (The building is unfit for its destination, it is unhealthy), as we make it for refrigerators, or for energy efficiency of buildings.
This acoustic indicator will have to take into account the various parameters of the acoustic comfort (reverberation, noises of equipments, impacts noise level, sound insulation), by integrating in particular the balance between them.
Peter Rogers, Cole Jarman, UK
How can a green building be truly sustainable without it having sustainable acoustics?
This talk will aim to answer this question and probably creating a whole lot more. It will expand on the plenary session presentation to explore in more depth why Green Buildings demand a fresh approach by acousticians, and what that could be. Have we being deafened by noise and unable to appreciate the need for positive sound. This is likely to provide plenty of scope for debate on this topic, with the aim of revealing a route map for what constitutes good acoustic design in the greener buildings of the future and how acousticians need to take responsibility and proactively expand their influence to getting the message across as each opportunity presents itself.
More time will be spent providing examples, tools and the ideal approach for various types of buildings, with one high profile office example being focused on as a case study. This is the WWF-UK HQ - Living Planet Centre, Woking, UK which aims to be a flagship green building.
Areas where further research and opportunities for development are needed will also be mentioned before opening the floor to the workshop and further debate.
Carsten Svensson, Saint-Gobain Ecophon. Sweden
Accessibility, acoustics and sustainability
A “society for all” has been on the agenda in several countries the last years – and still is! In line with this, buildings have to be accessible and usable for people also with disabilities such as limited orientation capacity. An important principle is that all people have equal rights and are of equal value. It is a principle of, for instance, the Swedish building legislation that all new buildings and those which are renovated should be fully accessible for disabled people. Since 2001 it has also been required in Sweden that easily eliminated obstacles to accessibility and usability should have been remedied before the end of 2010.
In order to give all people equal rights to participate in society, the built environment must be made accessible and usable also for people with disabilities. Moreover, what is good for disabled people is most likely also good for everyone else.
In terms of accessibility and usability, acoustics relates more to the concept of usability.
Usability means that people can take part in the environment and use it. Acoustics is primarily related to persons with limited orientation capacity, and a good acoustic environment, in this sense, primarily benefits persons with impaired vision and hearing, persons with cognitive difficulties and the elderly.
This presentation highlights who benefits particularly from good acoustics and how acoustics can be applied in practice with regard to accessibility and usability. Good acoustics is one parameters contributing to a sustainable world and acoustics certainly must be a natural part of sustainable design. Our hearing and aural sense directly affects our safety, communication, social health and wellbeing, thus our quality of life. Knowledge on acoustics and practical implications in the built environment affects the progress towards a sustainable future.
Jonas Skeppås, Saint-Gobain Ecophon, Sweden
TABS (Thermally activated building systems)
"A trend today in modern buildings is to use the ceiling as a cooling surface, to use thermally activated building systems (TABS). An advantage with this solution is the increased possibility to use sources for cooling such as ground or sea water since the large ceiling area can operate at a relative high cooling temperature. The ceiling can also store the cold air that is available during the night and the risk for draught and discomfort will also be reduced compared to traditional cooling with cool air.
A challenge arises when this system is combined with a requirement for good acoustics. The traditional solution – an overall, class A acoustic ceiling - does not work, as the cooling effect from the concrete is shielded by the ceiling. One solution is to use free-hanging units, which improve the acoustics in addition to allowing effective cooling. Ecophon has performed tests based on the European standard EN 14240:2004 in order to evaluate how the cooling effect is influenced by free-hanging units. This test has been combined with similar test reports from other parties in a general graph. The results indicate that much of the cooling is produced by natural convection and that it is important not to impede the air movement around the ceiling units."
Lily Wang, Erika Ryherd, Kerstin Persson-Waye, James Whitlock, Claus Møller Petersen, Valtteri Hongisto and Andrew Parkin give their insights into their work and EIAS2011.
Interview with Lily Wang
Interview with Erika Ryherd
Interview with Kerstin Persson-Waye
Interview with James Whitlock
Interview with Claus Møller Petersen
Interview with Valtteri Hongisto
Interview with Andrew Parkin
Claus Lynge Christensen (Odeon) - photo by Martin Arvebro
Room acoustic simulations and auralisation
Introduction text:
The aim of the workshop is to give the participants information on recent research in the field of room acoustic simulations and auralisations. The workshop will incorporate four key-note presentations that highlight interesting topics and applications in the field. The intension is that these presentations will inspire and engage to fruitful discussions during the workshop.
Moderator: Peter Svensson
Assistant moderator (Ecophon staff): Erling Nilsson
Opening lecture speaker (to all): Michael Vorländer
(Speakers in Work shop)
- Tapio Lokki
- Claus Lynge Christensen
- Peter Svensson
- Michael Vorländer
Workshop “Room Acoustic Simulations and Auralisation” at the Ecophon International Acousticians’ Seminar, 2011
Abstracts
Auralization of Sound Insulation
Michael Vorländer, RWTH Aachen University, Germany
Auralization is an established technique in room acoustic, but it is an interesting and powerful tool in other sub-disciplines of acoustics as well. In its usual definition, auralization means that a room is considered as system of sound transmission path and made “audible” by using excitation signals from appropriate sound sources. The key to achieve the resulting sound file is signal processing involving convolution with a filter response. The input data for such kind of auralization are based on standard building acoustics quantities such as sound reduction index, vibration reduction index and reverberation times, besides the basic room data of volume and surface areas. The problem in listening to auralized sound insulation is, however, the low level and low frequency content of the resulting signal which sets limits to the sensitivity and electrical noise in the electroacoustic reproduction system and to the background noise in the reproduction room. In this contribution the basic features of signal processing are discussed, and strategies for creating filters for direct and flanking sound transmission are presented and demonstrated with audio and video examples.
How to present auralized sound to a listener
Peter Svensson, Department of electronics and telecommunications Norwegian University of Science and Technology (NTNU)
Auralization involves the computation of a sound signal which then needs to be presented to a listener or "rendered", to borrow a term from the visual domain. This presentation will give a brief overview of the common formats that are used. The most common is the binaural format, which is based on computing the sound pressure signals at the ears of a listener. Such a format can be presented to a listener using headphones, or two loudspeakers and a crosstalk cancellation filter. Another category includes various multichannel loudspeaker formats. These range from the 5.1 format which is used for home cinema, as well as more advanced ones: amplitude panning for any number of loudspeakers, wavefield synthesis, and higher-order Ambisonics. The latter two formats aim at reproducing a sound field over an extended volume in space so that a listener can move freely within a limited region. Possibilities and limitations with all the formats will be outlined.
Understanding acoustics of new trends in room design by means of auralisation
Claus Lynge Christensen, Odeon A/S
The design of buildings for schools, offices etc. have undergone large changes in recent years. Open plan design has become mainstream offering large and light, visually appealing atriums which unites complete buildings into large coupled spaces including many different functions. Even if room acoustics parameters such as T30 and STI (Speech Transmission Index) can be calculated, they may not offer a clear basis for evaluation of the acoustic comfort; if noise from the canteen is disturbing work in other parts of the building volume or if one group can hear the conversation of another (speech privacy) etc.
This presentation gives a short overview of the calculation principles in Odeon and demonstrates how Odeon was used for auralisation in the first open plan high school built according to the intensions of revised Danish guidelines (2005) for high schools. Auralisation was used in order to evaluate acoustics in the building with different amount of absorption present. Sound transmission through walls was also evaluated. Auralisation examples are given.
Modeling 1D-diffusers - the missing link.
Bengt-Inge Dalenbäck, CATT
Many surfaces in a room can in geometrical acoustics be seen as 1D-diffusers. Examples are stage or side walls with vertical battens or ridges, ceilings with beams across or along the room, 1D QRD diffusers, and in general 1D corrugated surfaces. So far these surfaces have been modeled as 2D-diffusers where the reflection angle depends only on the angle to the surface normal, such as in the Lambert distribution, and appears to have essentially worked satisfactory. However, the larger the area of surfaces of this type that are used in a room, and when source or receiver is close to these surfaces, the more important it becomes to use a more suitable scattering model, especially so if the room geometry is non-mixing and with an uneven absorption distribution. A 1D-diffuser can be described as a surface construction that, in a frequency dependent way, mainly scatters sound incident perpendicular to the battens while for sound incident parallel to the battens the scattering is low, but not as low as for a flat surface due to the depth variation. This paper presents a way to model 1D-diffusers that is compatible with the data for 2D-diffusers where only the direction of the battens needs to be indicated. The experience from estimating scattering coefficients for 2D-diffusers can be directly used and the model allows for both randomizing a diffused ray, as in classical ray-tracing, and for efficient deterministic diffuse ray split-up as used in CATT TUCT.
Simon Smith (Sweyne Park School) - photo by Martin Arvebro
A workshop regarding open plan office acoustics was held at the Ecophon International Acousticians' Seminar, in Båstad, Sweden, Sept 22nd.
An opening lecture to introduce the workshop was "Acoustics in my School" (Essex Study) by Simon Smith - Learning Environments Manager, Sweyne Park School, Essex
A total of four presentations were held and discussed in the workshop that followed:
Educational premises (school acoustics): Workshop Moderator – Andrew Parkin (Cundall Acoustics)
David Canning - London Borough of Newham. UK
Essex Study
Bridget Shield - Professor of Acoustics, LSBU. UK
Understanding acoustics in open & semi open learning spaces
Monika Rychtarikova - Katholieke Universiteit Leuven, BelgiumInstitute of Acoustics, RWTH Aachen, Germany
Calculating the Optimum Reverberation Time and Absorption Coefficient for Good Speech Intelligibility in Classroom Design Using U50
Lennart Nilsson - Akustikmiljö AB, Huddinge/Stockholm, Sweden
Low frequency problems in classrooms
David Canning
The Essex Study
David Canning - London Borough of Newham. UK
Several years ago Essex County Council in the UK had faced repeated challenges to the working (functional) acoustic conditions in their schools. One school in particular served as a resourced provision for hearing impaired children. This school had been judged as an outstanding school by Independent Inspectors and it had considerable experience of educating hearing impaired children. The school was an unexceptional building, typical of many in the UK. Most of the teaching took place in virtually identical classrooms each with a volume of about 150 cubic metres. The challenge to the County Council was to create an environment that would meet the auditory needs of hearing impaired children in a working school. They had to find a solution that would be cost effective, and must not be detrimental to teachers or other children.
In order to identify the most suitable acoustic conditions a double blind counterbalanced controlled experimental design was adopted. The simplicity of the design was supported by considerable goodwill and intense periods of refurbishing classrooms at times when neither teachers not students would be in school. During the 6 month experimental period, three identical classrooms received different sound treatments in such a way that they appeared visually the same and a fourth was left untreated. Using a latin square design, the sound treatments were rotated between classrooms at appropriate periods and extensive performance measures were obtained for more than 100 lessons. Both qualitative and quantitative measures were obtained.
This workshop will present some important findings quantitative and qualitative findings the impact of reverberation time on working noise levels and signal to noise levels as measured at the children's ears. It will also look at the impact of teaching style and class size on functional acoustics.
Bridget Shield
Understanding acoustics in open and semi-open learning spaces
Bridget Shield, Professor of Acoustics, LSBU. UK
Open plan classrooms became popular in the 1970s in Europe and the USA in response to progressive educational movements, however their use was discontinued owing mainly to problems of noise and visual intrusion. In the 21st century educational and architectural trends are leading to a resurgence of open plan design, with many schools incorporating large open areas and atria intended to accommodate shared teaching space.
This presentation will report the results of a large scale, detailed acoustic survey of semi- open plan primary school classrooms in the UK, which have enabled acoustic design guidelines to be developed to ensure good listening conditions. However current acoustic and questionnaire surveys of secondary schools suggest that, even when open plan spaces comply with current acoustic performance standards, students have difficulty hearing their teachers in such spaces. The presentation will conclude by presenting interim results from the current surveys which raise questions concerning appropriate guidelines for large open learning spaces in secondary schools.
Monika Rychtarikova
Calculating the Optimum Reverberation Time and Absorption Coefficient for Good Speech Intelligibility in Classroom Design Using U50
Monika Rychtarikova, Katholieke Universiteit Leuven, BelgiumInstitute of Acoustics, RWTH Aachen, Germany
Acoustical comfort in general, and the quality of speech transmission from teacher to students in particular, are crucial in determining the quality of educational processes in schools. The acoustical treatment of interior surfaces, the sound insulation of surrounding constructions, the vocal capacity of the teacher, student activity noise, children’s abilities to hear and concentrate and the educational circumstances, are among the many factors in the
complex mechanism of speech understanding. Managing the rich variety of measures for optimising classroom acoustics demands a multidisciplinary approach.
In this article we propose a predictive model for speech intelligibility, as expressed with the parameter U50, based on objective acoustical values, i.e. the reverberation time RT, signal-to-noise ratio SN, and the relative proportions of sound arriving early and late at the listener.
The possible additional need for minimum RT values is also investigated in relation to the phenomenon of ’overdamping‘ in classrooms.
Lennart Nilsson
Low frequency problems in classrooms
Lennart Nilsson, Akustikmiljö AB, Huddinge/Stockholm, Sweden
Almost all classrooms have a reverberation time that increases dramatically at lower frequencies.
Normally the specified reverberation time is 0,5 seconds, which means a mean value between 250 and 4000 Hz. At lower frequencies it is not specified.
At 125 Hz it often reach 1,0 seconds and at 63 Hz it often goes beyond 2,0 seconds.
What happens is that we get a rather big masking effect and because of this the recommendation in the Swedish standard is to keep the reverberation time as short as possible at 125 Hz if it is to be used for people with a hearing impairment.
Otherwise it is not allowed to be increased more than 0,1 seconds.
At low frequencies we have a lot of standing waves giving longer reverberation and higher levels.
That gives masking effect both in time and level and even if it not directly affects the possibly to understand, it affects the concentration and increase tiredness.
There exist several ways to absorb low frequencies and it would be much to win to find easy effective ways to do so in order to get a higher output from the learning process in schools.
Click here for the full list of Abstracts from EIAS 2011 and the other workshops
Kerstin Persson-Waye (Gothenburg University) - photo by Martin Arvebro
The hospital gives acoustical challenges that affect both patients, staff and the hospital as a business facility. The aim of the workshop was to discuss the challenges of the hospital soundscape and how they can be addressed.
The workshop was chaired by Kerstin Persson Waye and presenters were Roger Ulrich, Erica Ryherd, Nicky Shiers and dr Gunnar Öhlén and dr Paul Barach also participated via a prerecorded film.
Claus-Moller Peterson (Grontmij) - photo by Martin Arvebro
A workshop regarding open plan office acoustics was held at the Ecophon International Acousticians' Seminar, in Bastad, Sweden, Sept 22nd.
An opening lecture about open plan offices was held by Christina Bodin Danielsson entitled "The future office – a meeting place or something else? Which are the acoustic challenges in the future office design?".
A total of four presentations were held and discussed in the workshop that followed:
"Questions on Open-Plan Office Acoustical Criteria" - John Bradley
"Final draft committee standard: ISO/FDIS 3382-3 MEASUREMENT OF ROOM ACOUSTIC PARAMETERS - PART 3: OPEN PLAN OFFICES" - Valtteri Hongisto
”Acoustic Tools and methods in open-plan offices” - Claus Møller Petersen
"Acoustic guidelines in the Netherlands" - Sara Persoon
"The future office – a meeting place or something else? Which are the acoustic challenges in the future office design?"
Christina Bodin Danielsson, PhD Brunnberg & Forshed Architects Ltd/The Stress Research Institute, Stockholm University. Sweden
In this opening lecture Christina discussed that the office has thus become a metaphor of a meeting point in recent years. Two questions needs to be asked if this holds true: a) Is meetings the major factor for creativity and innovation, and b) If so, what acoustic challenges do this mean for office design?
"Questions on Open-Plan Office Acoustical Criteria"
John Bradley, Institute for Research in Construction, National Research Council, Canada
The combination of Articulation Index (AI) ≤0.15 and Ambient noise (Ln) ~ 45 dBA specifies conditions of acceptable speech privacy for open-plan offices. The paper discussed these criteria and their validity, including how acceptable such conditions would be, and how practical it is to achieve them. The importance of using representative speech levels when calculating expected speech privacy ratings was stressed.
"Final draft committee standard: ISO/FDIS 3382-3 MEASUREMENT OF ROOM ACOUSTIC PARAMETERS - PART 3: OPEN PLAN OFFICES"
Valtteri Hongisto Finnish Institute of Occupational Health, Finland
The measurement arrangement contains a single speech source at one workstation and several measurement points at different distances from the speech source. In each measurement point, the speech level, background noise level, and STI (Speech Transmission Index) are measured. The data is used to derive two acoustic quantities which describe the speech privacy in the open-plan office at different distances from the speaker. The distraction distance, rD, and the spatial decay rate of speech, DL2S. These quantities together describe the speech privacy in open-plan offices.
”Acoustic Tools and methods in open-plan offices”
Claus Møller Petersen, Grontmij, Denmark
The presentation was based on results from the project "Limiting annoying noise in open plan offices" supported by a grant from the Danish Working Environment Research Foundation supplemented with results from other offices. The studies suggest a link between DL2 / DLf and work environment / organization in combination with architectural / furnishing conditions to describe the employees experienced satisfaction with the acoustic conditions.
"Acoustic guidelines in the Netherlands"
Sara Persoon, M +P - consulting engineers (part of Müller-BBM Group)
In the Netherlands, already many companies changed their traditional ways of working into a more modern working concept, so called New Work or Work New Style (Het Nieuwe Werken). This year a new Handbook Building Physics Quality for Offices was released by the Dutch Government Building Agency (Rgd) in cooperation with leading Dutch consultancies. In the Handbook acoustical parameters are given for designing an open plan office with different types of working places with a satisfactory level of acoustical comfort.
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