Recommendation for future work 56 a Alcons simulation at First Floor for Q=1 b Alcons simulation at

4.5 Discussion 53-54 5 CONCLUSION 5.1 Conclusions 55

5.2 Recommendation for future work 56

5.3 Benefit of the Project 56 REFERENCES 57-58 LIST OF FIGURE NO TITLE PAGE 1.1 The overall process of project 4 1.2 PSM 1 Gantt Chart 5 1.3 PSM 2 Gantt Chart 5 2.1 The reverberation time Tontechnik-Rechner 16 2.2 The graph of critical distance 17 2.3 An illustration of sound reflection in enclosed room 19 2.4 The illustration of reflection, absorption and transmission 20 3.1 The research flow chart for overall process 22 3.2 Sample of plan layout 23 3.3 Sample of parameters points. 24 3.4 a Loudspeaker between Floor and Wall, b Loudspeaker between Floor and Ceiling, and c Loudspeaker at flat surface ceiling-wall junction 25 3.5 The sample of unfinished contour plot 27 3.6 Step to changing the contour level 28 3.7 Step to set intervals 28 3.8 Step to generate mesh 29 3.9 Shaded band in planar form 29 3.10 The experiment process flow 30 3.11 The dimension of modified anechoic chamber 31 3.12 The process flow implementation new sound absorber 32 4.1 a SPL simulation at First Floor for Q=1 b SPL simulation at First Floor for Q=2 c SPL simulation at First Floor for Q=4 39-40

4.2 a Alcons simulation at First Floor for Q=1 b Alcons simulation at

First Floor for Q=2 c Alcons simulation at First Floor for Q=4 41-42 4.3 a SPL simulation at Second Floor for Q=1 b SPL simulation at Second Floor for Q=2 c SPL simulation at Second Floor for Q=4 46-47 4.4 a Alcons simulation at Second Floor for Q=1 b Alcons simulation at Second Floor for Q=2 c Alcons simulation at Second Floor for Q=4 48-49 4.5 The relationship between SPL and Alcons at Q=1 50 4.6 The relationship between SPL and Alcons at Q=2 50 4.7 The relationship between SPL and Alcons at Q=4 51 4.8 The SPL and RT60 by using dried rice straw and kekabu 52 LIST OF TABLES NO TITLE PAGE 2.1 Monopole sound source Q and d at various locations Rossing et al. , 2002 8 2.2 Methods used in Speech Intelligibility Predictor Paulraj et al. , 2010. 11 2.3 Classification of quality of Speech Intelligibility Score Ballou, 2008 13 4.1 Volume and surface area calculation 34 4.2 Parameter for RT60 34 4.3 Summarized calculation for RT60 and Dc 35 4.4 Distance between loudspeaker and microphone at First Floor of Masjid 36 4.6 Alcons values according critical distance at First Floor of Masjid 38

4.7 The distance between loudspeaker and listener at Second Floor