Acoustic characterization of Apulian Rupestrian churches

Rupestrian churches are a unique feature among Italian cultural heritages. However, due to their locations which prevent an easy access they are not well known to the public and not yet studied as needed. The research work aimed at filling this gap by acoustically characterizing three churches and by making the collected information available to the public on the internet using a friendly interface capable of integrating both visual and acoustic rendering of the space. The acoustic characterization is discussed here, together with a study of the hypothetical original conditions based on the analysis of the degradation process of the materials and of the finishing of the surfaces by means of an acoustic simulation model. Acoustic measurements were carried out with a portable equipment made of an omni-directional sound source, a pair of binaural microphones, and a B-format microphone. Impulse responses were measured in many points having the source located both near the altar and in the area occupied by the congregants. Recordings of the "natural" sounds of the sites were also made in order to ease the virtual fruition of the spaces as well as to characterize their soundscape and investigate possible influences on the choice of the sites.