The relationship between noise levels and academic performance is well documented – so much so that it’s recognized by LEED building certifications. Schools can earn points for classrooms with sound levels below 40dB, which are then used to qualify the school for different levels of certification, and in some instances, financial grants.
But in many classrooms, sound levels average 65dB (Oberdorster and Tiesler, 2005), which can make a big difference to students’ engagement with their learning, and in turn their academic performance. So today I’m looking at 4 ways you can improve classroom acoustics.
1) Amplify the Teacher’s Voice
Sounds from other children, HVAC systems and traffic noise can all interfere with teaching. Just four rows back from the front of the average classroom, speech intelligibility reduces by 50% (Siebein, 1998); and when children have impaired hearing, this problem is worsened.
Increasingly, teachers are relying on technology to amplify their voices so they can be heard over the other sounds. This will help when the teacher is addressing the whole class, but it doesn’t address the problem of high background noise levels.
This problem will remain, disrupting learning when students are completing their work, and will be exacerbated when they try and work in groups or engage with interactive learning: situations where they’ll be moving around and creating additional background noise.
2) Install Sound-Control Doors
Noise outside of the classroom can be a big distraction, but things like traffic and construction noise, and students in corridors or playing outdoors, are outside of your control.
Doors and windows are the main culprits for letting sound from outside into the classroom. Windows can be made more insulating with the installation of sound-reducing glass, but this is expensive – especially to upgrade the whole facility at once.
Instead, focusing on doors can deliver a similar level of improvement to background noise levels. The gap under and around the door will let noise in, so door seals can be installed to reduce the amount of noise from outside the classroom that can be heard indoors.
3) Install Acoustical Ceiling Tiles
If your school is in the process of a major redesign, installing acoustical ceiling tiles can have a dramatic improvement on classroom noise levels. These absorb more sound than standard ceiling tiles, which means they reduce sound reverberation in the classroom.
4) Soften up Hard Surfaces
Hard surfaces are terrible at absorbing noise. Unfortunately, classrooms are filled with hard surfaces: hard flooring, desks and plastic chairs. To reduce noise levels and improve classroom acoustics, it’s a great idea to soften up hard surfaces:
Upgrading to upholstered chairs will help to improve sound absorption, and have the added benefit of improving student comfort. Curtains or blinds at the windows will help to absorb sound within the classroom, and will also help to block sound coming in from outside.
It’s common for hard flooring to be used in classrooms, because it’s perceived as easy to clean. But hard flooring is very poor at absorbing noise, and is a major contributing factor to high background noise levels in classrooms.
Unlike hard flooring, carpet tiles excel at noise reduction. Cushion-backed carpet tiles are able to absorb 50% more noise than hardback carpet, which in turn absorbs 3x more noise than hard flooring.
Lowering the ambient noise levels in the classroom has been proven to impact students’ academic performance. And as well as improving noise levels by absorbing more sound, carpet has the added benefit of improving underfoot comfort, which will be greatly appreciated by teachers who spend all day standing.