Classroom acoustics: A case study of the cost-benefit of retrofitted interventions

Abstract

It is known that classroom acoustics is important for effective learning. To this end, many countries have developed classroom acoustics standards. However, research shows that these standards are often not implemented. Research evaluating the implementation of classroom acoustic standards internationally concludes that successful implementation is driven by mandatory standards that are part of building codes and that the cost of compliance is a barrier. The study presented here explores the cost of upgrading classrooms to achieve a suitable reverberation time. The paper presents a case study in South Africa, where acoustic standards are generally not implemented and cost and know-how are barriers. The objective was to optimise the cost, acoustic benefit, and accessibility of acoustic interventions. Four different acoustic interventions were temporarily installed in a classroom, simulating floating sound-absorbing ceiling panels constituting 25% of the ceiling area. The weighted sum model was used to assess the suitability of each intervention, taking into account the cost, acoustic benefit (in terms of reverberation time) and ease of access to purchase the materials. The case study demonstrates that a noticeable improvement in acoustic conditions can be achieved without significant cost and provides a basis for further research to develop simple standardised design recommendations.