Virtual model and acoustic characterisation of the ancient Roman theatre in Brescia

This paper deals with the ancient Roman theatre of Brescia. Built in the Augustan age (late first century BC - early first century AD), it was one of the largest roman theatres in northern Italy. The importance of the theatre is confirmed by its location, close to the Capitoline Temple and the Roman Forum. Over the centuries, major changes and damages occurred to the whole archaeological area. No acoustic investigation has been conducted before the one presented in this paper. On-site measurements were performed by using an Exponential Sine Sweep (ESS) signal. The impulse responses of the site were obtained through the Time Reversal Mirror (TMR) technique. Due to the current state of conservation of the site, the experimental results were not sufficient to describe the acoustic quality of the theatre; therefore, two numerical models have been realized, one referred to the original building and the other referred to the renovation occurred during the Severan age. Four different scenarios, relating to different configurations of coating materials and the presence of spectators, were simulated by means of a pyramid tracing software. The models allowed also to determine the acoustic quality parameters of the theatre. Thanks to the availability of the impulse responses obtained from the models, it was possible to convolve them with anechoic recordings, thus simulating the perception of different types of performances.