Speaker
Description
In open spaces such as amphitheaters or open-air concert venues, surprisingly large reverberation times can be found, despite the absence of the ceiling and side walls. Previous research on Greek and Roman theaters showed that reflections between the stage building and the steps in the audience area determine the main components in the impulse responses. So far, such models have been based on random-incidence scattering coefficients, and the results showed that a reverberant field can indeed be simulated in good agreement with measurement results in one-third octave bands. Periodic surface structures such as steps, however, lead to a specific directional scattering pattern with distinct frequency-dependent lobes. With more detailed characterization of this effect, particularly with narrow-band analysis, the reverberant field can be analyzed further. In the presentation, the simulation using the concept of bidirectional scattering will be presented, and the application in the above-mentioned case study.