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How accurate are Speech Intelligibility measurements in practice?
Bristish Institute of Acoustics organises a thematic meeting on that matter 26th September. IOA writes: "Some measurements appear to be more robust than others. (...) Which metrics are most reliable?If you are involved with any form of speech intelligibility measurement or are interested in the audibility of speech in any sort of environment, then this meeting is a must."
Anders Kjellberg, Professor, University of Gävle, has been granted € 215 000 for a research project on room acoustics, cognitive load and learning in speech communication.
Besides Ecophon, the project involves several Swedish research institutions in environmental psychology, learning and room acoustics.
The main focus of the project is to see how and why long reverberation makes learning more difficult. The project will run 2006-2010.
The project is originated from the scientific litterature review co-financed by Ecophon, and published as "Effects of Reverberation Time on the Cognitive Load in Speech Communication: Theoretical Considerations"
The grant is issued by the Swedish Council for Working Life and Social Research. Read more >>
"Sound design of open plan offices" is a Nordic research initiative, partly financed by the Nordic Innovation Center to identify room acoustic parameters and measurement methodology for open-plan offices. The objective is to guarantee an appropriate sound environment for open plan office workers. This includes extensive case studies of typical open plan offices in Denmark, Finland, Norway and Sweden.
Under the coming two years, the project will involve open plan and room acoustics specialists from five Nordic acoustic consultancy firms Helimäki Ltd, Delta Acoustics, Brekke & Strand, Erling Nilsson Akustik and Ingemansson Technology
Ecophon is initiative taker and owner of the project, to be ended 2008.
Project Manager is Anna Berglöw, Ingemansson Technology.
Communication of the findings to the architect profession as well as open office end-user organisations are important aspects of the project.
Extracts from project definition
"An increasing proportion of the working population in the Nordic region works in an office environment. At present open-plan offices are being built in every Nordic country. But the acoustic challenges are being tackled quite differently in each country (...)"
"One of the main reasons for open-plan offices is to facilitate communication amongst staff. At the same time, sound disruption is one of the biggest problems. yet, there are no parameters to describe the sound environment in open-plan rooms. (...)"
"The traditional measurements for acoustics in rooms were created on the basis of cubic geometries with good dispersal of sound energy (diffusion). Tthese are not suitable for the special acoustic conditions provided by open-plan offices (non-diffuse sound fields, geometric complexity, multiplicity of sources and recipients, complex sound propagation patterns, etc.) (...)"
Ecophon International Acoustician's Seminar will take place end of September in Helsingborg, Sweden.
A few seats are still available!
To get access to the registration zone, please contact Eric Henningsson, Project Manager.
Classroom Acoustics is a North American discussion forum for "anyone who is interested in public/private school listening and learning environments".
A recent discussion regards the acoustical contribution of drapes to classroom acoustics. Acoustician David Lubman, active member of forum writes recently that "Often children's listening needs are better served with good acoustical ceilings than with thick drapes."
Classroom Acoustics is a unique place where experts and end-users meet, exchange ideas, metods and solutions to improve the acoustics in educational premises.
Other North-American organisations address specificically classroom acoustics. For instance, access list of Classroom Acoustics publications available from the Acoustical Society of America
Physical activity teachers suffer more and more from tinnitus. Hearing impairment amongst sports instructors is a growing issue. Combining acoustic treatment with good impact resistance is the key to the solution.
Part of the new European standard (EN 13964:2004 Suspended ceilings - requirements and test methods) also covers the requirements on ball impact resistance. Ecophon provides solutions for all three classes (1A, 2A and 3A) in combination with excellent acoustic properties.
Short introduction to the three different classes:
The seminar, already presented here, has been allocated a corner on the Internet: you will find: registration, seminar programme, information about Helsingborg, miscellaneous, contacts, etc.
German Standard DIN 18041 "Acoustical quality in small to medium-sized rooms", previously addressed here is now available in English.
"Don't limit your senses - sound and the learning environment" is now available in an upgraded German version, entitled "Mit allen Sinnen lernen : akustische Ergonomie in. Bildungsstätten".
ISBN 91-974193-4-6 and ISBN 978-91-974193-4-5
"Don't limit your senses" has been recognised over the years as one of the few comprehensive sources of information on acoustics in learning environments. Among others, it is referred to by several public authorities and government bodies throughout the world.
The book highlights common problems found within the indoor environment in educational premises, it explains concepts and suggests measures to be taken. It covers research, legislation, case studies and advice on the learning environment.
"Don't Limit your senses" is also available in English, Danish, Swedish and Dutch, and can be requested in one of the language version from your national Ecophon office.
The Euronoise room acoustics session included 7 lectures last wek in Tampere (Finland). Important developments are taking place in that field. Promising!
Highlights from the session
- Rooms with ceiling treatment are not diffuse. Traditional, Sabine based relationships between reverberation time and sound pressure level do not apply. New calculations methods are needed, taking into consideration the scattering properties of furniture in the room. (Nilsson)
- Prediction of reverberation time in normal, non-diffuse rooms asks for specific models and methods together with an understanding of the decay process. European Standard EN 12345-6 raises questions regarding its usability, which should be taken into consideration in coming revisions. (Kylliäinen)
- Loudspeaker directivity seems to have a major influence on speech privacy measurements in offices. More precise directivity specifications are needed in order to allow for comparisons and establishment of guildeline values. (Sundin)
Most of these issues will be developped at the Ecophon 5th International Acoustician Seminar later this year. See previous post
Below the list of the 7 lectures. The downloadable papers involve Ecophon as co-writer.
- Room acoustical Applications of microperforated stretched foil, Christian Nocke, J. Pentila, C. Hilge
- Measurement uncertainty of the reverberation time and of others acoustical parameters changing model of microphone, Simone Geroso, Maria Giovannini, Renato SpagnoloMarco Filippi
- Sound scattering in rooms with ceiling treatment, Erling Nilsson, Pierre Chigot, Nils-Åke Andersson Download file
- The effect of resonators on the acoustics of coupled spaces, Dimitris Skarlatos, Tilemachos Zakinthinos
- Noise cancellation frontends for automatic meeting transcription, Marián Képesi, Tuan Van Pham, Gernot Kubin, Luis Weruaga, Andreas Juffinger, Michael Grabner
- Estimation of structural noise inside closed premise caused by external sources, Boris Goncharenko Poster
- Effectiveness of EN 12354-6 and other calculation methods of room acoustics in ensuring
required acoustic conditions in typical enclosed spaces, Mikko Kylliäinen, Pierre Chigot, Erling Nilsson Download file
- Sound source influence on speech parameters, Gunilla Sundin, Pierre Chigot
(This paper was included in another session, addressing speech privacy.) Download file
The classroom acoustics session at Euronoise consisted of 9 lectures on the 31st of May. Classroom acoustics was confirmed as a vivid area at the crossroad of room acoustics and occupational health.
Highlights from the session
- Stress indicators, such as heart activity are powerful to describe the incidence of poor room acoustics on teachers. (Tiesler)
- Improved room acoustics (T lowered from 0,7 s to 0,4 s) have an influence on sound pressure level in classroom. This influence is dramatically increased when it comes to modern teaching styles (see previous post on this subject) (Oberdoester)
- Dreadful room acoustic conditions have been measured in Italian sports halls. The risk of hearing damage is sometimes such that the teacher will leave the premises while the children are practising sports. Regulations exists and information to stakeholders is needed. (Maffei)
Below the list of the 9 lectures. The two downloadable papers involve Ecophon as a writer/co-writer.
- Noise a stress factor? - Room acoustics school ergonomics, Gerhart Tiesler, Markus Oberdoerster. Download file
- Room acoustics of classrooms with different shapes, Kurt Eggenschwiler
- Acoustical school ergonomics - a premise for "modern" teaching?, Markus Oberdoerster, Gerhart Tiesler. Download file
- Amplification in classrooms - the answer to students´ listening problems and teachers´ vocal strain?, Valdis Ingibjörg Jonsdottir
- Teachers' vocal symptoms related to their opinion regarding room acoustics, Valdis Ingibjörg Jonsdottir
- A field study on acoustic properties in German class rooms and their effect on the cognitive performance of primary school pupils, Jochen Seidel, Maria Klatte, Jürgen Hellbrück, Philip Leistner, Weber Lutz
- Acoustical conditions and noise exposure inside school gymnasium, Luigi Maffei, Paola Lembo, Gino Iannace, Pietro Nataletti
- Numerical estimation of student-activity noise and its impact on acoustical conditions in classrooms, Yulia Smyrnova, Andrzej Ossowski
- A procedure to improve acoustical conditions in classrooms, Yuliya Smyrnova
“It seems likely that improved acoustic conditions reduce risks of conflicts and errors.”
This is just one of the main messages from the research made in a coronary care unit in Sweden.
The study points out the importance of further research on possible effects of acoustics in healthcare on staff turnover, quality of patient care, and medical errors.
Acoustic measurements have been performed by Ingemansson Technology AB. This study was partly funded by Ecophon.
SUMMARY OF CONTENT
Aims:
To examine the influence of different acoustic conditions on the work environment and the staff in a coronary critical care unit (CCU).
Method:
Psychosocial work environment data from start and end of each individual shift were obtained from three shifts (morning, afternoon, and night) for a one-week baseline period and for two four-week periods during which either sound reflecting or sound absorbing tiles were installed.
Further results show:
- Reverberation times and speech intelligibility improved during the study period when the ceiling tiles were
changed from sound reflecting tiles to sound absorbing ones of identical appearance.
- Improved acoustics positively affected the work environment.
- The staff reported lower work demands and decreased pressure and strain.
The research concludes that important gains in the psychosocial work environment of healthcare premises can be achieved by improving room acoustics.
Earlier in Acoustic Bulletin, we communicated the outcomes of this psychosocial environmental research.
The OEM webjournal, an international peer review journal in all aspects of occupational & environmental medicine,
now has a free full text article available online.
