Evaluation of Reverberation Time in the Auditorium - Case of Assembly Hall of Engineering Faculty, Universitas Sebelas Maret

This research was conducted at the Assembly Hall or auditorium of Engineering Faculty UNS. This study aims to see the acoustic comfort and how to improve it by modifying the room material. The method chosen is the method with the least amount of modification. The method applied was measuring the room condition using laser distance meter and sound level meter, taking notes on the characteristic of the material used, and developing a simulation based on several modifications of the room materials. The result of the simulation was then compared to the standard of reverberation time. The study concludes (1) the acoustic condition in the room is indeed not meeting the standard to ensure users comfort, (2) the reverberation time is better when additional plasterboard ceiling is built. The simulation in this study was done through the help of Ecotect 2011. Keywords— acoustic, material, reverberation time This research was conducted at the Faculty of Engineering Main Meeting Room with the aim of improving acoustic quality, especially the improvement of reverberation time (RT) of this space to fit the auditorium standards. To achieve this goal, major changes are made to the ceiling material because it has the most impact on space acoustics. Ceiling is also one part of the building whose material is easier to modify. Other parts that are also modified are walls and floors. I. ACOUSTICS AND REVERBERATION TIME CALCULATION A. Acoustics The Oxford Dictionary defines acoustics as “relating to sound or the sense of hearing”. In physics, the term acoustics is used to explain the properties or qualities of a room or building that determine how sound is transmitted in it (Oxford University Press, 2017). In the classroom, there are three components to consider when studying room acoustics as these components affect users’ information reception. The three components are ambient noise, reverberation and signal to noise ratio (SNR). Ambient noise, or sometimes called background noise, is the prevailing noise level in a specified environment measured in the absence of the noise being studied (Ziobroski and Powers, 2005). Ambient noise may be produced externally, for example the sound of rain, traffic, or operating powerplant outside the room. Internally, the noise may be generated by the noise from PC or laptop used, light blasts or simply users’ conversation. Signal to Noise Ratio (SNR) compares the signal (direct sound or prime sound) to the noise. Basically, SNR is used to understand the quality of the signal transferred to users. Higher ratio is usually considered better specification because it means that the prime sound is louder than the noise (Altunian, 2016). Better level of SNR ensures 18th International Conference on Sustainable Environment and Architecture (SENVAR 2018) Copyright © 2019, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Engineering Research, volume 156