Design and Effect of Guiding Sound for Pedestrians While Maintaining the Streetscape Perception

There are many reasons to direct the flow of people in urban environments: avoiding overcrowdedness during large-scale events, minimising contacts during a pandemic or redirecting pedestrians in case of temporary obstructions such as accidents. In practice, this is largely achieved through visual means such as signage, via physical barriers or by police officers. These approaches have in common that they visually change the environment, which might negatively affect people's experience. In this paper, we explore stereophonic guiding sounds as an alternative crowd flow management technique, which does not visually affect an environment. We designed three different sounds to attract pedestrians that we played back on parametric loudspeakers to localise them precisely in space. We evaluated them in a study with 16 participants, who were asked to navigate an urban environment that we projected in an immersive video environment. Our results show that this approach is generally feasible, that sounds can motivate people to take a detour, and that the type of sounds affects the degree of motivation. The work reported here thus provides new insights into using stereophonic sound as a spatial user interface in controlling the flow of people in urban environments.