Space Replay, a project by British design students Francessco Tacchini, Julinka Ebhardt and Will Yates-Johnson, is listening to your every word. Taking the form of a menacing black sphere, it floats around aimlessly, recording everything it hears. Later, it plays those sounds back, echoing the human activity it just witnessed.

As otherworldly as Space Replay feels, it’s mechanics are quite simple. The orb is a ballon that’s been filled with enough helium to hover at a relatively consistent level, and there’s an audio recorder and speaker encased inside.

The group says it was interested in exploring the surveillance culture, which pervades its native London and abroad. “We aimed to draw people’s attention to their acoustic surroundings and the temporary way in which we pass through public spaces,” they told Dezeen“Creating a device that records the noises we make raises sinister questions about the ever-present surveillance in our urban environment.”