Every moment, the hearing system provides us with clues about the perception of our surroundings. We are able to roughly determine directions and distances of sounds in everyday life. However, to protect us from acoustic overstimulation, this ability remains relatively passive. The project Hearo includes a set of tools with which our acoustic perception of space can be actively explored. The toolbox is mobile and allows an experimental approach at various locations. During playful usage, the user encounters unexpected situations repeatedly.