Acoustical simulation, design and experimental investigation of a classroom: A case study

To improve teaching and learning conditions, room acoustics tries to adjust the educational environment. This research addresses the room acoustics of a small classroom in the Department of Mechanical Engineering at Isfahan University of Technology. It has been studied by modeling and simulating the classroom in the COMSOL software using the ray tracing method, and the reverberation time has been calculated. The model is validated by field measurements and using the impulse response function according to ISO ۳۳۸۲-۲ in terms of the reverberation time. Then, it is compared with Eyring's and Sabin's empirical relationships, as well. The acoustics modes of the classroom have been obtained using the modal analysis in the COMSOL software. ANSI/ASA S۱۲.۶۰ is employed to design a suitable acoustical environment for the classroom and absorption panels and bass traps are utilized to reach the desired condition. After applying the adjustments, the reverberation time reached the recommended standard value, which increases the sound quality. Other acoustical parameters such as Definition (D_۵۰), Clarity (C_۵۰) and Sound Transmission Index (STI) have been calculated before and after the acoustic correction. Results revealed that speech intelligibility has fallen in the acceptable range.

Keywords:

Room acoustics , reverberation time , COMSOL , Ray tracing