Acoustical performance of Brazilian dwellings: party walls

Abstract

This paper presents a study on the architectural evolution of Brazilian dwellings along the centuries, from a perspective that is distinct from other historical approaches: the sound insulation. Initially the most important events that have modified the use patterns of houses and, consequently, changed their acoustical performance are described. The second part of the article presents an investigation on the main building systems along different periods of Brazilian history, considering their relationship with acoustical performance, and discusses the theory of the transmission loss of single panels. Then, analytical predictions of the sound insulation are made for the party walls that were selected as the most important ones in the historical study. As results, the decrease in the acoustical performance of building partitions along history is quantified. The study pointed out that ordinary partitions found in the vast majority of new Brazilian residential buildings perform worse than the ones in older buildings: some walls have an average insulation of about 20 dB lower when compared to the ones used in the past.