Acoustic Evaluation of the Garrett Hall of the National Theatre D. Maria II in Lisbon

Abstract

The acoustic environment characteristics of a room in which artistic activities are presented to the public have a major importance on the experience of both the artists and the audience. Thus, it is important to study the sound field behaviour and characteristics in such rooms, particularly its three-dimensional impulse responses both at the audience level but also on stage. This paper presents an in-depth assessment of the acoustical characteristics of the Garrett Hall in the National Theatre D. Maria II in Lisbon, using a 1D and a 3D approach. Due to its history and the cultural significance, this theatre is a very important landmark on Portuguese culture. It is, therefore, of major relevance to characterize it from an acoustical point of view, to ensure the preservation of its acoustic signature if future modifications to its geometry or other architectural features which may impact Acoustics ever occur. Furthermore, a thorough assessment of the hall’s acoustic characteristics had never been carried out before. The acoustical characterization is achieved using the standard measurement procedures, according to ISO 3382, with an omnidirectional microphone and a dodecahedral loudspeaker, and using a 64-microphone array acoustic camera to record three-dimensional impulse responses for further processing.