Usman Haque, Sky Ear, 2004.

The artist testing part of the structure, March 2004.

This non-rigid "cloud" is embedded with mobile phones. The balloons contain miniature sensor circuits that detect levels of electromagnetic radiation at a variety of frequencies. When activated, the sensor circuits cause ultra-bright coloured LEDs to illuminate. The cloud glows and flickers brightly as it passes through varying radio and microwave spaces. As visitors to the event call into the cloud to listen to the distant electromagnetic sounds of the sky, their mobile phone calls change the local hertzian topography; these disturbances in the electromagnetic fields inside the cloud alter the glow intensity of that part of the balloon cloud.

Courtesy of Usman Haque.