Individual control as a new way to improve classroom acoustics: A simulation-based study

Previous studies indicate that acoustic improvements at classroom-level, such as using ceiling panels, do not work well to solve noise problems in classrooms. Therefore, this study introduced a new way - individual control - to improve classroom acoustics. The acoustic effect of five different classroom settings is simulated: two individual-level acoustic improvement settings (Single-sided canopies and Double-sided canopies), two classroom-level acoustic improvement settings (Half-ceiling and Full-ceiling), and one Control setting. The simulation was accomplished with Computer Aided Theatre Technique (CATT-Acoustic (TM)), which is a ray-tracing-based room acoustics prediction software package. According to the two main ways of using classrooms (instruction and self-study), the simulations were run for two situations: instruction situation and self-study situation, and the Lombard Effect was taken into consideration in the self-study situation. The results showed that in both situations, all of these improvement settings, compared with the Control setting, could shorten the reverberation time and increase the speech transmission index, and the improvements caused by the individually controlled canopies were more obvious than caused by the ceiling panels. Additionally, in the instruction situation, the individual-level improvements could increase the sound pressure level of the teacher's speech, while in the self-study situation, the individual-level improvements could decrease the sound pressure level of other children's talk. In the future, it is recommended to produce and test different individually controlled devices in a lab or real classroom to verify these results. (C) 2021 The Author(s). Published by Elsevier Ltd.

Automated summary

This study introduced a new method of individual control to improve classroom acoustics, which was found to be more effective than traditional classroom-level acoustic improvements in reducing reverberation time and increasing speech transmission index. The simulations considered instruction and self-study situations, and showed that individual-level improvements can impact the sound pressure level differently for teacher's speech and other children's talk. Further research is recommended to test different individually controlled devices in real classrooms.