Calculation of reverberation time in rectangular cross-section spaces: Formula development based on daad software and modification of sabine formula

The use of empirical formulas in calculation of reverbation time has been and stil is a significant area of study among the scientists who have been both improving the available formula and suggesting new ones with different approaches and criteria. Despite their advantages in making the calculations easier, empirical formulas are not considered enough when it comes to the accuracy of the results they provide. Besides, acoustic simulation softwares and the measurements in real spatial environments have taken an important place in the world of acoustics, especially in the last 20 years. The aim of this dissertation is to propose a modification on the Sabine Formula, used in the calculations of the reverbation time in rectangular spatial environments and to establish new reverbation time formulas. In this dissertation, an acoustical simulation software, named ?DAAD?, with the ability to do calculations using the ISO standarts has been developed. The ?DAAD? software uses ray tracing as the modelling method. The software is capable of calculating EDT, T20 and T30 values for given sources and receivers. In the next step, the rectangular spaces were determined and the calculations were done for the source and receiver points. Six rectangular spaces different in volume, but same in dimensions were selected and the ?Booner room proportion?, which is considered to have a good sound propogation in regard to the room modes, have been used for room dimensions. Some specific values have been applied in absorption, source and receiver points and room sizes because of the endless variables in the study. The achieved values have been statistically analysed and three main conclusions have been obtained. 1. Developing new reverbation models based on the results of the analysis, a. Specifying the difference between source and receiver locations within the new model viii b. Specifying the differences in EDT, T20, T30 values within the new models 2. A modification of the Sabine Formula, a. The insertion of the variability between source and receiver point to the Formula b. The insertion of the the variability in EDT, T20, T30 values to the Formula 3. The evaluation of the distribution of the parameters in the enclosed spaces that had been calculated.