The ?Listening Walker? was produced as part of the ?Terra Dynamica? project (www.terradynamica.com), funded by the French government. The installation has been created for the exhibition ?Urban stimulations? in Paris during the ?Futur en Seine? Festival in 2013. It is a stand-alone interactive sound installation designed as a video game with different levels of exploration. It is also a part of a research project, the goal of which is to analyze writing styles used in interactive sound installations and to propose new authoring tools for composers. The version presented at DigiFest illustrates the scripting style where the narration takes the player?s point of view. Such an installation shows the evolution of the composer?s role from that of a deterministic creation to a non-deterministic one. The player?s goal is to discover a virtual district of Paris. When the walk begins, neither the plot, nor the buildings or the inhabitants are fully perceived. Then, Non Player Characters (NPCs) appear, moving around the listener. They are interpreting his moves and the time spent listening to particular sounds. According to the listener?s attitude, each NPC has his or her own particular reaction such as running away, getting closer to the listener, ignoring him or helping him to discover secret paths in the city. Depending on the player?s listening behavior, the city emerges progressively from the ground. Compared to a "real game", there is almost no challenge, and no time limit. Listening curiosity and the stability of the player?s relationship with the NPCs create the personality of the visit. Development of this project relies on the CryEngine and Fmod technologies and uses the assets, the map of Paris and the technologies that were created for the Terra Dynamica project. The original installation presented in Paris used a WFS (Wave Field Synthesis) 3D sound system and a large screen in front of the player. The same installation can also be exhibited using binaural spatialization for the player (headphones) and stereo for the audience.