Written by Guest Post on July 17, 2015 .
Mai-Britt Beldam is a Concept Developer in the education sector for Ecophon Denmark. She believes that teachers, pedagogues and students deserve a great sound environment. We read about a study she did surrounding sound in the classroom and we invited her to write a guest post for us. Here is her piece.
Sounds. Sounds have always been important for me and when I graduated from high school I chose to study French — because of the music in the language. Phonetics became my favorite subject! After a job as a teacher in France I continued to study — this time ancient Greek. The ancient constructions now had my attention. Life came along and today I feel that I ‘combine’ my passion about sounds and constructions working with room acoustics in learning environments — even though my Masters Degree never predicted this actual future. I have worked for Saint-Gobain Ecophon, for 8 years. Saint-Gobain Ecophon develops, manufactures and markets acoustic products and systems that contribute to a good working environment by enhancing people’s well-being and performance.
Being a teenager
Do you remember what it was like to be a teenager? Hanging out with your best friends during recess — chit chatting with your friends even though the teacher had already arrived in class? Simply having a great time socializing in school. Now — imagine what this would be like, if you couldn’t hear. Because of noise and of bad speech intelligibility in the classroom. And because you were hearing impaired in a room with bad acoustics. This was the case for a 5th grade student in a small village, Thorning, in Denmark. She was sick and tired of going to school, she was struggling to do her homework and her social life was limited to writing text messages to her grandmother during recess.
Building regulation in Danish schools
In Denmark we have a building regulation saying that room acoustics in schools have to be good. Actually we need reverberation time to be short (0.4–0.6 sec). BUT this regulation only concerns new schools and refurbishments and it means that old schools can have really bad acoustics — which was the case in Thorning. In the hearing impaired girl’s classroom reverberation time was more than a second…
The intervention study
Ecophon and Comfort Audio decided to do a study together in the hearing impaired girl’s classroom to see if she and the other students would be affected by a combination of acoustical treatment and the best FM/digital hearing systems. We did performance tests (working memory and listening tests) before and after the intervention to see if we could see any trends. The findings were remarkable. We tested the students both in silence and with added background noise and the hearing impaired girl especially showed us that she had really high learning potential — when she could hear. Normally in Danish schools we have a lot of group work, a lot of interaction and ‘classical/traditional teaching’ is not very common today. This leads to noise and ‘Lombard effect’ if the acoustics are bad. The constant background noise made it impossible for the girl to ‘shine’ and to benefit from her great potential and the results revealed this. When we mounted a new acoustical ceiling and wall absorbers — she scored as good in noise as in silence and she showed everybody that she was the top performer of the class!
What we couldn’t measure
Not only did the hearing impaired girl do better in her tests after the treatment of the room — the whole class benefitted from the changes and scored better. That’s a fact. What we couldn’t measure was the teacher telling us that her headache was gone and that the other teachers complained about why they should continue to teach in the ‘old rooms’. We couldn’t measure what maybe was most important: After the treatment the hearing impaired girl’s grandmother never got text messages anymore –simply because it was now possible for the girl to hang out — to chit chat — to be social — to be happy with her friends because she could finally hear and interact!
A strong school leader
After the intervention study the school leader contacted the municipality (in Denmark most schools are owned by the municipalities and it is their responsibility to manage the facilities). She told about the results in the class and she explained about the ‘acoustic situation’ on her school in general — and she managed to get approx. 7.5 million DKK (= 1 million Euros) from the municipality to refurbish the school.
Miracles do happen
The miracle is not the intervention study showing that good room acoustics is necessary in schools — and especially if you are hearing impaired — because we have known that for years! The miracle is that it is finally possible for ‘our’ girl to be a teenager just like her friends — and to be the top performer of her class!
Facts about the measurements of the room
In the classroom we measured both reverberation time and speech clarity. Reverberation time went down remarkably and now meets the strongest demands for teaching. Speech clarity (C50) is not in the Danish regulation but it is an acoustic descriptor that’s really important in rooms for teaching — and especially if you are hearing impaired. The improvement here is really noticeable, since you register a difference of only one decibel.
Originally published at www.lios-group.com on July 17, 2015.
