Imagined Systems is an interactive sound installation creating a virtual space filled with imaginary machines and objects. As visitors passed under spotlights in particular ways, for example in a counter clockwise motion for a large turbine wheel, the virtual devices would respond with appropriate sound. Drawing on everyday sounds collected over the years—a potato hissing in the microwave, unintelligible radio babble from a cab in Queens, an alarm at the airport, oil dripping in the pan of a cooling engine—the sounds are remixed into a scene that cannot be placed, perhaps vaguely reminiscent of Pittsburgh’s industrial past.

The work was created for 2011 Pittsburgh Biennial at the Pittsburgh Center for the Arts. The visitor is presented with a darkened, empty room illuminated by three spots of light on the floor. Hidden 3D cameras fed video to computers running custom computer vision, physics, and sound synthesis programs driving a four-channel speaker system.

Below is a brief sample of the audio from one point during the piece’s lifetime.
Imagined Systems by ukle

The first piece I have made to explore this concept features invisible wind chimes. When a person walks through the space occupied by the virtual chimes, they begin to ring. Should the actor stop to explore the source of the sound, he will uncover a fine-grained, predictable, knowable system. Using computer vision techniques to detect movement in a space, real, physical objects are able to interact with virtual, “physical” ones. Although not concrete, they are still physical because a physics simulation ensures the individual chimes still hang behave in ways we know and expect. They hang from the ceiling by strings, collide with each other (causing them to ring), swing and respond to gravity by eventually settling back to rest, and respond to touch by a soft body (muting any ringing).

Invisible Chimes is an intangible, interactive system that prompts us to consider how we acquire knowledge of complex systems from limited experiential data. The chimes, though installed in a space, cannot be seen, and while they can be touched, they cannot be felt. The only indication of their presence is the sound they make. Nevertheless, the system is still very much a “physical” one, in that the chimes are governed by the laws of physics. Although they can be appreciated by simply walking through them, further interaction reveals that the individual chimes can be separated, muted, and lifted, and that they behave in a predictable, understandable way. The inset video reveals the physical model the custom software uses to create the interactive system.