Acoustic characteristics of Pompeii theatres: a novel method to spatial sound analysis

“Architecture is frozen music”, “music is flowingarchitecture”1. Ancient theatres are spaces that embody this philosophy perfectly. Not only should they be documented in beautiful words, but scientificresearch is essential. Acoustics gave birth to a branch of scientificresearch in the purely artistic study of music. The Greek science of acoustics carried out a mathematical study of the treble range in musical performances and a study of physical phe-nomena2. Conversely, Vitruvius did not limit himself to theoretical specula-tions on acoustics but focused on architectural applications3. He provided a clear explanation of the role of each component in the acoustics of the the-atre, which led to a practical improvement in the quality of musical perfor-mances. The acoustic characteristics of the theatres studied have important re-search implications.Researchers who have invested in a comprehensive examination of this his-toric architectural heritage have benefitedenormously from the development of measurement methodologies. As a result, in addition to characterising the architectural characteristics of these performing arts venues, these techniques may now be used to comprehend the direction of arrival of sound lines dur-ing the analysis of Impulse Response measurements (IRs). This study aims to acoustically characterise the ruins of three ancient theatres in Pompeii: the Roman theatre, the Amphitheatre, and the Odeon theatre. The authors creat-ed acoustic maps that used spherical array microphones and screenshots from overlay videos. The acoustics of the Pompeii theatres were investigated and the analyses were refinedby detecting sound reflectionson the architectural surfaces.