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

Dadi Zhang,Martin Tenpierik,Philomena M Bluyssen

doi:10.1016/j.apacoust.2021.108066

Dadi Zhang, Martin Tenpierik + Show 1 more

Open Access

https://doi.org/10.1016/j.apacoust.2021.108066

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Journal: Applied Acoustics	Publication Date: Apr 7, 2021
Citations: 8	License type: cc-by

Affiliation: Delft University of Technology

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.

Highlights

In the past decades, the acoustic conditions in classrooms have drawn much attention
The background sound levels were kept as the default setting in the CATT; for the four improvement settings, the background levels were calculated based on the following equations: DLP
10 log Acon Aimp where DLP is the difference of background sound level between the control setting and the improvement settings; the Acon is the amount of sound-absorbing area in the control setting; Aimp is the amount of sound-absorbing area in the improvement settings

Summary

Introduction

The acoustic conditions in classrooms have drawn much attention. Current conditions of acoustic quality in classrooms as well as effects of poor acoustics on children’s health and performance have been studied [1,2,3], and many acoustic guidelines have been issued [4,5]. A previous Dutch study indicated that noise is the biggest indoor environmental problem in classrooms: 87% of primary school children reported to be bothered by it [6]. Some other studies showed that poor room acoustics have an adverse impact, on children’s school performance [8], and on their later life [9,10]. To create an effective learning environment, many recommendations and standards on classroom acoustics have, been developed

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