Investigations on sound energy decays and flows in a monumental mosque

This work investigates the sound energy decays and flows in the S€uleymaniye Mosque in _
Istanbul.
This is a single-space superstructure having multiple domes. The study searches for the nonexponential sound energy decay characteristics. The effect of different material surfaces and volumetric contributions are investigated using acoustic simulations and in situ acoustical measurements.
Sound energy decay rates are estimated by Bayesian decay analysis. The measured data reveal double- or triple-slope energy decay profiles within the superstructure. To shed light on the mechanism
of energy exchanges resulting in multi-slope decay, spatial sound energy distributions and energy
flow vectors are studied by diffusion equation model (DEM) simulations. The resulting sound
energy flow vector maps highlight the contribution of a sound-reflective central dome contrasted
with an absorptive carpeted floor in providing delayed energy feedback. In contrast, no multi-slope
energy decay pattern is observed in DEM simulations with a bare marble floor, which generates a
much more diffuse sound field than in the real situation with a carpeted floor. The results demonstrate that energy fragmentation, in support of the non-exponential energy decay profile, is due to
both the sound absorption characteristics of materials and to their distributions, as well as to relations between the subvolumes of the mosque’s interior.