A black floating orb that drifts through stairwells, elevators, corridors and other transitional public spaces, recording ambient sounds and conversations, playing them back, layering the soundscape with a 'delayed echo of human activity'.

Space Replay is a joint project by Royal College of Art students Julinka Ebhardt, Francesco Tacchini and Will Yates-Johnson designed as an experiment in manipulating our familiar environments by confronting us with equally familiar sounds – replayed in unexpected places.

The spectral installation is formed of a latex balloon filled with enough helium to lift the battery-powered Arduino, hacked Wave Shield sound device and speaker contained inside. It hovers using natural air currents to dictate its direction.

It's another example of poetic public art capitalising on sensory input to generate atmospheric new experiences of the environment as embodied in projects such as Studio Roosegaard's Dune installation, Cyclique's sound-responsive LED balloons and Yuri Suzuki's Garden of Russolo phonographs.