The contribution of wave diffraction effects in ancient buildings has been already examined for the prehistoric Stonehenge monument in England as well as the Maya pyramids. Especially for the study of sound propagation around finite surfaces and boundaries such as in room acoustics, it is increasingly evident that the sound field is properly described by both reflected and edge-diffracted components which can only partially be computed by the established geometrical acoustic methods. in underwater acoustics, aeroacoustics, building acoustics and electroacoustics. Diffraction phenomena have been studied in many diverse fields of acoustics, e.g. Wave diffraction constitutes a significant component of sound fields that is generated within many real-life environments and geometrical spaces. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In all cases, the contribution of sound diffraction components is examined via its contribution to speech intelligibility from signals generated in the theatre’s orchestra and from a virtual reconstruction of the stage-scenic building. The contribution of the diffracted sound to the total sound field is identified through a detailed and novel analysis of energy-based acoustic parameters, via the time and frequency responses as well as of the spatial parameters relating to listener-perceived effects. The analysis accounts for direct, reflected, diffracted and mixed reflected – diffracted paths and the theatre’s acoustic response is numerically evaluated in various positions along the koilon slice, accurately matching to in-situ measurements. This study examines a 3D model of an elementary slice of the seating benches (“koilon”), evaluating the generated sound field in the time, frequency, and spatial domains. Especially for the distant listener positions, an accumulation (“avalanche”) effect from lower tier diffracted energy is identified.
![first order diffraction of sound first order diffraction of sound](https://img.youtube.com/vi/2Ih7KzKLLWA/maxresdefault.jpg)
It is increasingly evident that in such theaters, sound diffraction at the edges of the multiple tiers generates significant source signal amplification. * Corresponding author: work provides an in-depth investigation on the effect of sound diffraction in the acoustics of the ancient theatres, with reference to the theatre of Epidaurus. Konstantinos Kaleris, George Moiragias, Panagiotis Hatziantoniou and John Mourjopoulos *Īudio & Acoustic Technology Group, Electrical & Computer Engineering Department, University of Patras, 26504 Rio, Greece