'Echoes' is an interactive sculpture which builds upon the architectural walkway designed by Boffa Miskell. It senses movement from people walking through the walkway at CIAL and transfers this movement into pulses of sound and light throughout the entire length of the walkway. Visitor's activity triggers the speed and direction of the pulses. Like ripples in a pond, as multiple 'echoes' cross each other, patterns form.

Mounted at hip height in each of the 36 archways are two pairs of infrared sensors which send a signal to a Touchdesigner server every time somebody crosses the infrared beams. By having two 'sensor-receiver' pairs in each archway, the server can work out both the visitors' direction and walking speed by calculating the time difference between each beam being broken, allowing us to create a corresponding echo. The server processes the data and turns it into DMX signals which control the series of 4 lights mounted to the archways, and sound triggers fed to speakers built into the archways, with subwoofers along the ground, creating the 'echoes', or ripples of light and sound.
The 'echoes' are designed to show how visitors affect their immediate environment, and how they affect others' environment at other positions along the walkway also, with subtle gameplay elements as multiple 'echoes' combine. It was essential to ensure the experience was secondary to the main task of getting from A to B; we didn't want it to interfere with the flow of people in the airport, nor be something people felt they had to work out. Instead, our goal was to add a little moment of wonder and magic at the final, or beginning stage of the airport visitors journey.