How to Improve Acoustics in a Classroom (Full Guide)
Both student and teacher performance is highly dependent on classroom acoustics. Based on the research carried out by two experts, Oberdorster and Tiesler, in 2005, the average acoustic levels in many classrooms are 65 decibels. In comparison, average home noise is 40 dB and 60 dB is the loudness of a normal conversation.
It becomes apparent that trying to hear a lecture while having to deal with obnoxious background noise can be rather difficult. The before-mentioned report states that sound levels are a crucial factor to the learning capabilities of students, which influences their academic performances.
However, annoying background noise and echo can be easily thwarted by making small adjustments to the classroom. I also recommend reading my article on how to soundproof a room if sounds coming from outside the classroom are part of the problem.
Having said that, improving the acoustics in a classroom can be done with the following steps:
1. Amplify the Teacher’s Voice
The teacher’s voice may be unable to reach the students due to background noise. According to Siebein (1998), the speech intelligibility of teachers reduces by 50% for students who sit four rows from the podium of a standard class, from where the teacher speaks. This percent increases for special scenarios where the student has hearing difficulties.
Small, wearable microphones can amplify the teachers’ pitch during lectures, so that students who sit beyond the fourth or fifth rows can conveniently hear. These technologies are effective in that they can intensify teachers’ voices to a level that exceeds the external noises from traffic, HVAC systems, and other noisy areas.
The challenge of external noises interfering with the lectures will persist; however, voice amplification will ensure that all students can at least hear the teacher well. This is the first improvement to consider, because it’s easy to implement and very effective.
For teachers who intend to utilize voice amplifiers when teaching, you can visit online shopping platforms to buy effective and affordable types. Examples include the excellent Gicey Portable Voice Amplifier and Bluetooth Portable Voice amplifier from Amazon.
2. Insulate Doors and Windows
If you’re in the process of installing new doors and windows, the general rule for sound insulation is the thicker/heavier, the better. A heavy wooden door is better at blocking noise than a hollow wooden door. A double pane glass (insulating glass) window is better than a single pane window.
Another significant factor are gaps and cracks commonly found on window and door frames. Covering the gap on the frame with foam tape will reduce the area through which sound can move freely. A significant gap is found under the door. You can eliminate this gap by placing a basic silicone door sweep or an automatic door sweep on the bottom of the door. Here’s my review article for both options.
Also consider hanging curtains on the classroom windows to soften this area and reduce sound reverberation. Thick, noise-dampening curtains are the best option for sound and thermal insulation. Unfortunately, they also block sunlight. However, you could simply cover the windows when it’s appropriate and move them away when it’s not.
3. Soundproof And Soften Walls
Along with doors and windows, classroom walls are the main barrier blocking external sounds. They’re also the big surfaces on which sound bounces off. So consider doing two things to improve acoustics:
- REDUCE ECHO: Place soft furniture and plants near the walls, add acoustic panels on the walls.
- SOUNDPROOF THE WALLS: By installing mass loaded vinyl directly on the wall studs and/or placing rockwool batts between the studs. If you can’t reach the studs, invest in soundproofing panels that can be installed directly on a wall surface.
4. Arrangement of Seats
When the arrangement of seats is in rows, it tends to intensify the effect of background noises in the classroom. Arranging seats in angles allows for a more effective learning process, as more students can conveniently hear the teacher.
5. Acoustical Ceiling Tiles
These acoustical ceiling tiles possess the ability to trap noises and limit the occurrence of echo and reverberation in the classroom. Standard and regular tiles do not possess the trapping ability and this allows the noise caused within the rooms to disrupt the teachings.
Rhino Acoustic absorption panel and Seedream Acoustic panels are examples of quality ceiling tiles and panels you can conveniently order on Amazon. These and similar tiles are made from polyester fiber and refined with quality acoustic treatment.
6. Softening Other Hard Surfaces
Rooms in schools built with hard floors and surfaces are unable to suppress, limit, or absorb the noise coming from within. The hard surfaces in the rooms are not specific to the walls or floors, but it extends to other things within the class, such as the desks, chairs, shelves, and boards.
The noise in the classrooms intensifies when it is filled with furniture made from hard materials. We can improve the level of sound or acoustic by softening these hard surfaces. The softening process may include any of the following:
This includes the finishing touches made on the furniture. Usually, the main material on chairs, desks, and shelves is wood or steel, and this is a hard material.
Using an upholstery material for chairs, desks, and shelves can improve the acoustic. Furnishings of window blinds and curtains, when made with soft upholstery is also helpful.
You can also add soft furniture pads to the bottom of chair and desk legs. These pads, asides from helping to reduce vibrations and noise, also eliminate floor marks.
Hard floors are common in most schools because they’re easier to maintain, but they’re obviously not ideal when it comes to acoustics. Considering covering the hard flooring with carpet tiles or similar materials as I explained in this article.
If the floor is being renovated or is under construction, there are many other valuables additions. For example, green glue and floor floaters can reduce the squeakiness of the floor. Installing a subfloor will add thickness that will reduce noise transmission between your classroom and the downstairs area.
Remember, the quality of classroom acoustics primarily depends on two factors:
- The echo, caused by sound bouncing off of hard surfaces, which can be reduced by covering these surfaces with softer materials.
- Sounds coming from outside the classroom, which can be reduced by improving sound-blocking capabilities of walls, doors, windows and the floor, depending on where exactly the noise is coming from.
Other problems to consider are the noisiness of the students themselves, and the distance between the teacher and the students. In both cases, louder teachers and students will fair better. For that reason alone, voice amplifiers are becoming an increasingly popular solution for classroom environments, especially when it’s required to speak for longer periods of time while wearing a mask.
Hope this helps!