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.

Investigation of the Acoustics Performance of the University’s Lecture Rooms by using Economical and Feasible Design Improvement Strategies

“…The detailed configuration for surface treatments is presented in Table 2. In a prior investigation conducted by Abdullah et al (2020), the ODEON software was utilized to implement acoustic improvements in university classrooms located in Malaysia. The simulation incorporates gypsum board and perforated plywood as materials for treating the walls and ceilings.…”

“…As mentioned by Acoustical Society of America ( 2000), installing a new lay-in ceiling suspended from the original ceiling is one of the treatments that can reduce the RT to desirable condition. In addition, the simulation method demonstrated that optimal RT conditions in classrooms can be attained by substituting reinforced concrete walls and microfiber ceilings with gypsum board and perforated plywood that is 12 mm thick (Abdullah et al, 2020). An adequate number of absorptive materials are required to be placed on the ceiling, walls, and floors to achieve a suitable RT for classrooms (Sundaravadhanan et al, 2017).…”

Acoustic Characterization of Rooms Using Reverberation Time Estimation Based on Supervised Learning Algorithm

“…The reverberation of a space has positive and negative aspects: in fact, if a certain value of the reverberation time helps to reinforce the direct sound it therefore improves listening; on the other hand, an excessive value of the sound tail compromises its quality [1,2]. For good reception, both in the case of speech and in the case of music, it is necessary to contain the decaying tail of reflected sound from a source and ensure a good spatial distribution of the sound field inside the room so that all listeners can perceive and appreciate the sound regardless of the space in which they are located [21].…”