What is realistic enough? Design considerations for soundscape simulators

Urban soundscapes reflect life and behaviours in a city. Given the dynamic and ever-changing behaviours of people, this introduces many complexities for soundscape simulators. We focus on bottom-up simulators, wherein every aspect of an environment can potentially be simulated, including 3D models of spaces, people’s behaviours, sound sources, weather, nature, lighting, and the physics behind them to create the illusion of navigating a real space. How much realism is necessary in such virtual environments though? This work discusses realism through the lenses of plausibility, hyperrealism, and ecological validity. Is it ok to just be a plausible reality? Should reality be exaggerated? How faithful should it be and from which perspective (e.g. matching physical or cognitive “realities”)? These questions were considered during the development of our in-house soundscape simulator, City Ditty. City Ditty seeks to be operable by non-sound professionals and support integration into urban projects with minimal expertise and resources, thus encouraging more diverse urban professionals and city users to contribute to how their cities will sound through participatory approaches. Given these requirements, we discuss how suitable levels of realism can be attained to fit people’s needs at technical, practical, and theoretical levels by considering these three lenses for design.