Advanced techniques for the determination of sound spatialization in Italian Opera Theatres

As Italy possesses a rich heritage of Opera houses and since, owing to the period in which they were built, they were not planned for electroacoustical amplification systems and the quality of the listening conditions in the theatres was still wholly due to their spatial characteristics, the materials and the techniques used to build them, the Teatro Comunale of Bologna was chosen for this research. An experimental measuring campaign was conducted in this late 18th century “Italian-style” theatre so as to define a map of the impulse responses (IR) able to significantly represent the acoustics perceived by the audience seated in the stalls or balconies. Using the geometric and constructional data, a three-dimensional model of the theatre was then made and used to numerically simulate the acoustic properties in the theatre and, after appropriate calibration, the respective impulse responses were calculated in the same points as where the measurements had been taken in the experimental campaign. Lastly, the method for auralising an anechoic signal was used for qualitatively comparing the simulation of the theatre’s acoustic response. This was done by calculating an IR from the experimental data and extrapolating an IR from the numeric model.