ACOUSTIC IMPROVEMENT DESIGN OF CLASSROOM BASED ON SPEECH INTELLIGIBILITY AND DIFFUSIVITY LEVEL USING RAY-TRACING METHOD

• Main Author: KURNIA PUTRI (NIM : 13311040); SOFIA THARRANNISA (NIM : 13311056), RIMA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20456
• Institution: Institut Teknologi Bandung

University classroom is a space used by students and teachers for academic purposes. Classrooms require optimum acoustic conditions since speech is the main activity of the whole activities in classrooms. Initial measurements show that classrooms do not yet have optimum acoustic conditions. In this research, improvements for university classrooms acoustic based on clarity of speech and sound diffusivity level are designed using modelling and simulation approach with ray-tracing method and image source model. This study refers to the ANSIASA S12.60-2009 standard. Simulations consisted of two main stages; validation stage and design stage. Validation stage was performed by comparing existing condition of the measurement and simulation results. Design stage included the addition of acoustic panels on the walls and improvement of ceiling and floor materials absorption performance value. Based on the results of simulation design with ray-tracing method, quality of clarity of speech in the classroom has increased. Reverberation time value in the small classrooms have a range of 0,49 - 0,62 s and 1,14 - 1,51 s in the large classroom. For the D-50 parameter, small classrooms have a range of 70,41 - 78,89 % and large classroom have a range of 48,33 - 49,81 % at frequency range of 500 – 2000 Hz. The small classrooms have good and excellent STI with a value range of 0,69 – 0,76, and the large classroom has fair STI. Based on coherence value, classrooms are yet to have a diffuse sound field because the coherence value is still below 0,8.