Good teaching requires good acoustics—what SIA 181/1 means for schools
A classroom is one of the most acoustically challenging spaces there is. Thirty people, a speaking voice, lots of background noise—and right in the middle of it all, children who have to pick out that one voice from all the others in order to learn.
How well this works depends less on the children's talent than on the space itself.
— The average child in Switzerland spends about 2,118 days in school during the legally required period of schooling.
Studies show that poor acoustic conditions have a greater impact on children’s speech intelligibility than on that of adults, with direct consequences for their ability to learn and their academic success. Children simply lack the linguistic background knowledge to automatically fill in the gaps in what they’ve partially understood, as adults do. If a excessively long reverberation time is added to the mix, a sentence that would otherwise be understandable turns into an acoustic guessing game.
What the SIA 181/1 standard specifically requires
This is exactly where SIA 181/1 comes into play: with clear target values for reverberation time in classrooms, calculated based on the room’s volume. For a classroom with a volume of approximately 250 m³, the target value when occupied is about 0.6 seconds. By comparison, an uninsulated room with a concrete ceiling and hard surfaces often has a reverberation time several times that value.
No one grades the acoustics of a classroom. Nevertheless, they shape every lesson that takes place there. SIA 181/1 does not treat this as an abstract recommendation, but rather as a verifiable criterion: A room either meets the standard or it does not.
Anyone who renovates or builds a new school is not only making decisions about walls and windows, but also about how well a child in the back row can hear the teacher.
Marino Lauber
The author knows this problem from personal experience: how much concentration it takes to be in a noisy room, and how much easier it is to listen in a quiet one.
