The majority of buildings are acoustically isolated from the outside. Yet, together with the undesired noise, the the inner building is cut off from the soundscape of the local community, the animal life and the weather. The ‘Membrane‘ is an architectural sound device that transforms outdoor noise into habitable indoor sound. Like a biomembrane, the device acts as a selectively permeable barrier for sound. The streetscape is captured by an outdoor microphone and filtered so that only selected frequencies of the signal pass. Through an exciter speaker, the processed sound is played back into the inner window. An interface allows the user to adjust the volume of the outside as well as the degree of the transformation. The noise is not experienced as waste, but as a resource for an ever-changing, pleasant and calming acoustic atmosphere. The ‘Membrane’ allows a meaningful relationship to outside, harmonizing the needs of the persons inside with the liveliness of their environment.