On the acoustical measurement and modeling of large complex environments: the case of St. Anthony’s Basilica in Padua

As part of the acoustical characterization of St. Anthony’s Basilica in Padua, an investigation has been performed to evaluate factors that may affect sound propagation in large architectural environments having a complex geometry and coupled volumes, aiming at the optimization of the electro-acoustic sound diffusion systems. The interior, built in the 13th century, has a volume of 82000 cubic meters, including the seven domes surmounting the nave, the transept and the apse, and the ambulatory that surrounds it. In the first part of the work the sound field inside the Basilica has been measured in the current situation, using different techniques and different types of sources and excitation signals. At the same time the vertical temperature gradient has been measured by means of sensors distributed within the environment. Subsequently, a 3D geometrical model has been created and the sound propagation has been simulated via ray tracing technique, focusing on the acoustic conditions related to the different liturgical events which normally take place in the Basilica. The simulation study has been carried out with the aid of the experimental data previously acquired, which allowed a careful calibration of the model including the air absorption coefficient.