Six-Degree-of-Freedom Audio Rendering Using Spatial Impulse Responses in an Urban Context

Abstract

Many acoustic studies on urban environments focus on soundscapes and subjective perception, analyzing environmental parameters such as loudness, fluctuation strength, and roughness. However, room acoustic parameters have rarely been applied in this context, even though public squares are frequently used for musical events. Considering classical concerts in historical or archeological sites in Italy, or pop music performances in public squares amplified through audio systems, a key challenge is that the acoustic characteristics of these spaces remain largely unknown. This study addresses this gap by conducting acoustic measurements in Piazzale San Francesco in Parma, a public square already used for summer musical events, and by implementing its audio rendering in a virtual reality (VR) environment. The acoustic survey was carried out following the standards for enclosed rooms, in accordance with ISO 3382, while the digital model of the space was created using photogrammetry. The piece Ti tradì quell’alma ingrata from Il Trovatore was used as the audio signal in Unreal Engine, enabling a navigation of the digital space calibrated with measured impulse responses (IRs). The resulting VR rendering allows users to be fully immersed in the virtual space, freely exploring it with six degrees of freedom (6DoF), as they would in reality, while listening to the same musical performance.