Potential acoustic treatment analysis using sabine formula in unoccupied classroom

Abstract

Effective teaching and learning, not only taking into account the good teaching methodology and facilities but the acoustic level in the classroom should also be addressed. RT-60 is the time required for sound decay in a classroom. The time taken for the sound to decay depends on the absorption coefficients (α) of surface material and the volume of the room. This paper aims to identify potential treatment materials for improving the value of RT-60 of the selected unoccupied teaching hall/classroom at one of the higher learning institution in Malaysia. The value of RT-60 is calculated using Sabine formula and used the same parameter like the surface material, surface area, and room’s volume identified in previous research. The best RT-60 value is 0.6s for the classroom with 10k-20k cubit feet in volume and it coincides with the volume of the selected classroom which is about 14320 cubic feet. To ensure that room has the optimum RT-60 values, the materials used on the ceiling, walls, floors, windows, and doors are assessed for sound absorption rate and then materials with appropriate absorption coefficient are proposed for improvement purposes. As a result, it found that gypsum board is suitable to use for wall and plywood 12mm thick is proposed for ceiling material. By applying this proposed material will then enhance the acoustical performance of the unoccupied teaching hall especially in RT-60 value.