A COMSOL–MATLAB Coupled Optimization Framework for Cost-Effective Acoustic Renovation of Educational Buildings Using Wood-Based Materials

Poor classroom acoustic conditions can impair speech intelligibility, increase cognitive load, and reduce the quality of learning environments. Simulation-guided optimization provides a promising approach for improving building acoustic performance and indoor environmental quality while reducing trial-and-error material selection in renovation practice. The field-validated optimized configuration combined slotted wood sound-absorbing panels and mineral wool panels, with a total material cost of 1512 RMB. Field measurements showed that this configuration reduced RT from 2.42–1.76 s to 0.78–0.43 s. In addition, the simulation-based STI evaluation increased from 0.19 to 0.75, indicating a potential improvement in speech intelligibility. Since STI was not directly measured in the field, this result is interpreted as a model-based prediction supported by the calibrated RT validation. The average relative error between simulated and measured RT values was 6.83%, demonstrating the predictive reliability of the calibrated model for RT prediction. The proposed framework provides a practical decision-support method for cost-controlled acoustic renovation of educational buildings and was validated using an existing classroom case. The framework was demonstrated using one existing classroom and provides a methodological basis for adaptation to other educational spaces by updating room-specific inputs. Its external transferability requires validation in additional classrooms.