Individual control as a new way to improve classroom acoustics

Abstract

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™), 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.