This year Euronoise was held in lovely Crete (close to the Knossos Palace) from the 27th to 31st of May – and in the impressive surroundings more than 700 delegates from all over the world attended more than 50 structured sessions in total.
Room acoustics were on the agenda every conference day and this article aims to capture the main takeaways and my favorite presentations from the session called ‘Effect of room acoustics and noise on speech intelligibility and task performance in schools’.
Nicola Prodi and Arianna Astolfi were chairing the session and Arianna started the session with her own presentation focusing on smaller kids – ‘Effects of classroom acoustics on potential struggling first-grade readers.’
The study she was presenting was focusing on children in the first year of primary school and if there is a link between dyslexia and acoustics – and if acoustics is important for potential struggling first grade readers. Arianna mentions in the beginning of her talk that if there is a link it is most likely due to impairments in phonological procession (rapid processing of sounds in words) and that kids with dyslexia often also have problems with rhythm (e.g. clapping).
The study included 7 primary schools in Turin, Italy, and 12 different classrooms. Acoustic measurements were done in both occupied and non-occupied classrooms. The German DIN 18041 was used as a guideline and the results from the measurements showed that none of the classrooms lived up to the standard (all the classrooms had reverberation times above the guideline values).
The study included four scenarios/cases – and the study investigated both the effect of a training program in bad acoustic conditions, a training program in good acoustic conditions and also acoustic conditions only (no training program).
So – what effect did the training and acoustic conditions have on the children?
Arianna concluded the following:
- Classroom acoustics is ‘unsatisfactory’ in classrooms without sound-absorbing treatment.
- Some recently renovated classrooms have a ‘good’ acoustic quality, but none is ‘excellent’.
- When the training program was associated with ‘good acoustics’, a greater significance of the difference between some reading abilities at the end and the beginning of the school year emerged.
- Better results are expected in classrooms with ‘excellent’ acoustics, which will be object of investigation in a following part of this particular project (‘Ascolto 3’).
Another presentation (by Bovo Roberto), ‘Speech perception in noise by young sequential bilingual children’ also looked at acoustics and sound in relation to children’s performance. This presentation concluded that when immigrants learn their second language (L2) the SNR is really important – and the years of exposure to L2 and SNR for words in noise were significantly correlated (p=0.034). On the other hand, the native language differences (Slavic cs. Roman) were not correlated with SNR.
Bovo Roberto concluded that for L2 learners 15 dB SNR in the classroom could still be insufficient for adequate scholastic achievements (even in classrooms with relatively short RT 0.3-0.7 sec).
Teenagers and open learning space – from small children to older students…
Ella Braat-Eggen presented her findings in her presentation ‘Open-plan study environments: effects of background speech and RT on a collaboration task’ – a really interesting presentation about what influence background speech has in open learning environments – and if different languages and reverberation times will affect the students differently (or if it is only the sound pressure level that is important).
Ella discussed how learning spaces have changed during the years and how open plan study environments are more and more normal. She mentioned that these new open learning environments are not to be seen as open offices since the use is different: the students don’t have to be there, they come and go as they please and don’t stay for eight hours a day. Libraries in particular is one of these ‘new’ open study environments where the students do group work and collaborative project work.
The study investigated 5 different scenarios:
- Absorbing – Swedish speech
- Absorbing – Dutch speech (mother tongue of the students)
- Reverberant – Swedish speech
- Reverberant – Dutch speech
The students had to solve a collaboration test in pairs and doing the task they couldn’t see each other’s pictures and had to rely on their ability to hear only. They had 3 minutes to solve the task and afterwards they were asked to answer a questionnaire about the annoyance of the background noise.
Ella concluded that longer RT in your own language was most disturbing – which was really not what they expected (they expected clear speech to be most disturbing) and she also concluded that you always have to look at RT in a real life condition because it affects the speech really much.
Open learning spaces – from monologue to dialogue
It is no secret that we see different ways of teaching and learning in Europe. Ella’s study from the Netherlands shows that traditional teaching (where the teacher controls the situation and often has a monologue in the classroom) happens less and less in her country, and this trend is also seen in Scandinavia, UK – and is more and more well-known in Australia and New Zealand.
Colin Campbell had an interesting presentation about going from monologue to dialogue in learning environments – and what impact that has on the sound in the classroom / open learning space – AND what room acoustic conditions we should aim for.
In his proceeding, ‘Acoustic impact on effective teaching and learning activities in open learning spaces’ Colin not only presented results from an open plan school in the Netherlands – he also compared the findings to both schools in England (the Essex study), Germany (Witzenhausen) and the ILETC project in Australia. (ILETC – The Innovative Learning Environments and Teacher Change project is an Australian Research Council (ARC) Linkage Project funded for 4 years from 2016-2019 lead by The University of Melbourne).
Before digging into acoustics Colin explained the different ‘outcome’ of teacher-centric and student-centric teaching/learning methods and he referred to the ILETC study that states that more desirable teacher mind frames and more behavior associated with deeper learning are linked with less teacher-centric classroom dynamics. Interestingly, Colin said, there is a considerable variance in cellular classroom outcomes when the more or less teacher-centric approaches are compared.
A classroom is not just a classroom and Colin presents a model from the ILETC study to show the different ‘steps’ you can see going from classical cellular spaces to open learning environments.
When it comes to sound and acoustics in open plan learning environments, Colin pointed out that speech communication for both teacher and student collaboration should be optimized to be clear and intelligible over short distances within class zones. However, beyond class zones speech is perceived as noise and should be kept to a minimum, to reduce the spread of sound causing general disturbance between different learning spaces. This means a specific need to balance good speech intelligibility locally, whereas in contrast over distance, poor intelligibility giving speech privacy between learning zones.
What might be more important than acoustics (!) – is that if you want to have success with an open plan school / learning environment you need to start with defining the educational vision – how are we going to practice learning/teaching in this school?
Leadership is also most important and Colin pointed out that an open plan school can be perfect one day and awful the next if management changes and if suddenly the future principal does not support and understand how to move from teacher-centric to student-centric teaching/learning.
What about light?
Another brilliant presentation was done by DTU professor Cheol-Ho Jeong – and for the first time (for me) in a room acoustics session a proceeding was about lighting. Cheol-Ho presented the paper ‘Noise measurements during focus-based classroom activities as an indication of student’s learning with ambient and focused artificial light distribution’. The study is done in collaboration with one of the biggest architects’ offices in Denmark, Henning Larsen, and it was refreshing to learn about how artificial light distribution impacts students’ learning during focus-based learning activities (e.g., mathematics, reading, and paper-based activities).
The noise levels during focus-based activities were measured in a Danish primary school with different lighting conditions. The study compared 20 fair conditions in terms of activity type and number of students, and it was found that the noise levels of the 70% of the measured cases got lowered adding focused local lighting – instead of the more ‘normal’ default lighting from the ceiling. Of 14 improved conditions, 11 cases showed an audible improvement between 1 and 3 dB (lower sound pressure level), and 4 cases with more than 3 dB was found, which is regarded as a significant improvement.
This potentially implies that the students can focus on the class better, and accordingly the students learning could be higher. The average improvement in the noise level was not huge, but clearly above the perceptual noticeable difference.
(Click here to read an article by Cheol-Ho Jeong – on another topic: The Problem With Acoustic Simulations).
All in all the session was diverse and interesting – and I’m looking forward to see more articles about main take-aways from the conference.