Church of São Miguel Arcanjo das Missões Jesuíticas: Influence of the Choir Positions on the Acoustic Parameters

Abstract

In recent decades, the appreciation of cultural heritage has reflected the growing concern with the conservation of historical values. However, acoustic characteristics have not always been considered as one of the values ​​to be rescued and, in this context, churches and cathedrals can be interpreted as important symbols of the values ​​of a given time. The São Miguel Arcanjo Reduction integrates a set of ruins of the Sete Povos das Missões, one of the main marks of the Jesuit and European Baroque missions of the Iberian Peninsula integrated into the indigenous culture of southern Brazil. Currently in ruins, the recovery of the structures began in 1925, being declared a World Heritage Site by UNESCO in 1983. The objective of this work is to carry out the acoustic reconstruction of the church of São Miguel Arcanjo through computer simulation. The implementation of the 3D model was carried out considering the liturgical organization reported in historical records. The software CATT-Acoustic v9.0c was used and four different choir positioning hypotheses and the respective changes in the parameters EDT, D50, C80 and STI were comparatively analyzed. The results of the parameters indicate that the quality of verbal communication is better in spaces destined for civil authorities, in the central nave close to the altar. It was evident in the comparative analysis of the acoustic parameters of the four choir positioning hypotheses, the social hierarchy used for the occupation of the central and lateral aisles, which also corresponds to different levels of sound perception.