This study focuses on the acoustical characteristics of Üç Şerefeli Mosque, built in between 1437and 1447 during the reign of Sultan Murad II in Edirne, which was the second capital city of the Ottoman Empire before conquest of İstanbul. The Mosque was utterly damaged by fire in 1732 and by an earthquake in 1748, then restored in 1764. At its time of construction Üç Şerefeli Mosque was the grandest of Edirne mosques, specifically its dome, and the greatest architectural achievement of the Ottoman architects. It had become a prototype for its successors, representing the transitional architectural style of typical Seljuk mosques towards to the Ottoman style. Within the scope of this study, initially the field tests were carried out in its unoccupied condition, in order to archive the current acoustical conditions. Basic room acoustics parameters are evaluated, including T30, C80 and STI. Acoustical simulations are utilized to investigate the occupied conditions of the mosque. Ray-tracing and diffusion equation model (DEM) computations are applied to comparatively analyze the modeling techniques of posture positions. DEM is also used to visualize the contribution of the dome in energy fragmentation within the mosque, through energy flow vectors and volumetric sound energy distribution maps.