The Challenge of Noisy Classrooms
Noise is one of the most overlooked barriers to effective teaching and learning in South African schools. Typical classroom construction relies on concrete floors, plaster walls and metal roof sheeting, all of which are highly reflective surfaces. When sound bounces off these hard finishes it creates prolonged reverberation, overlapping echoes that turn spoken words into an indistinct wash of noise. According to the Acoustical Society of America, “students in noisy classrooms may miss up to 25% of what their teacher says.” For a subject like mathematics or a second-language lesson, that missing quarter can mean the difference between understanding a concept and falling behind.
The problem is compounded by external noise sources common across South African schools: traffic on adjacent roads, construction activity, neighbouring classrooms with open windows, and playground noise during break times. Combined with reflective interior surfaces, these factors push background noise levels well above the thresholds recommended for effective speech communication. Schools in Johannesburg, Cape Town, Durban and Pretoria all face variations of this challenge, regardless of whether they are independent colleges or public institutions.
How Noise Affects Learning Outcomes
Research consistently demonstrates that excessive classroom noise undermines academic performance. Bradley and Sato (2008) found that “a 10-decibel reduction in background noise improved speech recognition scores in primary school children by up to 25 percentage points” (Journal of the Acoustical Society of America). When students strain to hear, cognitive resources that should be devoted to comprehension and problem-solving are redirected to the basic task of decoding speech. The result is reduced concentration, slower reading development and lower test scores.
The effects are not distributed equally. Crandell and Smaldino (2000) noted that “poor classroom acoustics disproportionately affect children with learning disabilities, non-native language speakers, and younger students whose auditory processing is still developing.” In a country with 11 official languages, where many learners are taught in their second or third language, this finding carries particular weight. Younger children in foundation phase classrooms are especially vulnerable because they have not yet built the vocabulary and contextual knowledge that allows adults to mentally fill in missed words. Addressing classroom acoustics is, in many ways, an investment in equitable access to education.
The Impact on Teachers
Students are not the only ones affected. Teachers working in reverberant classrooms must raise their voices to be heard, particularly when addressing learners seated beyond the first few rows. Over weeks and months this leads to vocal strain, fatigue and, in many cases, chronic voice disorders. Teacher absenteeism related to voice problems is a documented concern in education systems worldwide, and it has a direct impact on continuity of learning. When classroom acoustics are improved, teachers can speak at a natural volume, conserve energy and maintain engagement throughout the day.
Klatte, Lachmann and Meis (2010) found that “reverberation times above 0.6 seconds in classrooms significantly reduce speech intelligibility, particularly for students seated beyond the third row.” In many South African classrooms, reverberation times exceed this 0.6-second threshold by a considerable margin, meaning that a significant portion of the class is operating at a disadvantage before the lesson even begins.
How Acoustic Panels Improve Speech Clarity
Acoustic panels work by absorbing sound energy that would otherwise reflect off hard surfaces. When a teacher speaks, the direct sound travels to students while reflected sound bounces around the room. If those reflections arrive more than about 50 milliseconds after the direct sound, they interfere with speech perception rather than reinforcing it. By placing absorptive panels on walls and ceilings, the strength and duration of these reflections are reduced, bringing reverberation time down to a level where speech remains clear and intelligible throughout the room.
The effectiveness of an acoustic panel is measured by its Noise Reduction Coefficient, or NRC. Audial’s PET felt panels are available in three thicknesses, each with a different absorption rating: 12 mm panels achieve an NRC of 0.45, 18 mm panels reach 0.65 and 24 mm panels deliver 0.80. For most classroom applications, 18 mm or 24 mm panels provide the absorption needed to bring reverberation below the 0.6-second target. The choice of thickness depends on the room volume, existing surface finishes and the degree of acoustic correction required. Full technical specifications are available on the materials page.
Recommended Solutions for Schools
There is no single approach that suits every classroom. The best acoustic treatment depends on room dimensions, ceiling height, surface materials and the types of activities that take place in the space. Wall-mounted panels are the most common starting point, as they are straightforward to install and can be positioned at the height where first reflections are strongest. In rooms with high ceilings, suspended acoustic ceiling clouds or vertical baffles are particularly effective because they intercept sound before it reaches the hard ceiling surface and reflects back down.
For multipurpose halls and shared learning spaces, a combination of wall panels and ceiling treatments often delivers the best results. An acoustic assessment helps identify the specific issues in each room and determines the optimal panel placement, coverage area and thickness. Audial offers site assessments for schools across Johannesburg, Cape Town, Durban and Pretoria to ensure that every installation is based on measured data rather than guesswork.
Case Study: Dainfern College Junior Prep
One of the clearest examples of what acoustic treatment can achieve in a school setting is the Imaginarium at Dainfern College Junior Prep. This shared learning and cafeteria space presented a significant acoustic challenge: high ceilings and hard surfaces created excessive reverberation that made the room difficult to use for group learning, presentations or quiet reading. The solution involved installing suspended Aura Felt acoustic ceiling clouds, which reduced the reverberation time by approximately one second. The transformation was immediate and measurable, turning a problematic space into one that supports both focused learning and communal dining. You can see examples of similar installations in our project gallery.
Why PET Felt Panels Are Ideal for Schools
Safety, durability and sustainability are non-negotiable in educational environments. Audial’s acoustic panels are made from Recycled PET plastic and are fire rated, non-toxic and low VOC, meeting the strict requirements for use in schools and childcare facilities. The panels are lightweight, moisture-resistant and dimensionally stable, which means they will not warp, sag or degrade over time, even in humid coastal climates or hot inland conditions.
Design flexibility is another advantage. With 48 colours available and full CNC cutting capability, panels can be shaped into custom patterns, school logos or wayfinding elements that contribute to the learning environment rather than detracting from it. Younger learners respond positively to colour and visual variety, and acoustic panels offer an opportunity to enhance classroom aesthetics while solving a functional problem. Browse the full palette on the colour library page to see what is possible.
Getting Started with Classroom Acoustics in South Africa
Improving classroom acoustics does not require a full renovation. In many cases, strategically placed wall panels and a set of ceiling clouds can bring reverberation below the 0.6-second threshold and deliver a noticeable improvement in speech clarity. The process begins with an acoustic assessment to measure existing conditions, followed by a tailored recommendation for panel type, placement and coverage.
Audial works with schools, architects and education departments across South Africa to design and install acoustic solutions that fit within project budgets and timelines. Whether you are planning a new school building or upgrading existing classrooms, get in touch to discuss how acoustic panels can support better learning outcomes for your students.