In the age of the rapidly evolving touch screen, and all the creative interfaces it has spawned, it’s the rare gadget that’s capable of surprising us with an unexpected sensory experience. Knock Knock delivers just that. More of a counting box than a true calculator, the wooden box absorbs knocks, and then talks back–also in knocks–to give a mathematical answer. “The goal was to create a design piece that explores the sense of touch, but I wanted to create something warmer and more likable than tablets and smartphones,” designer Khalil Klouche tells Co.Design. “When a machine responds using the same language as the user, it feels like a dialogue.”
The wooden box contains four microphones, each within its own compartment. When you knock on the top, the microphones in each quadrant listen, and the one receiving the strongest signal processes the sound. Klouche programmed an Arduino board that connects with an electromagnet in the center of the box, where the response knocks happen.
Klouche, who created Knock Knock for an exhibit at the Museum of Design and Contemporary Art (MUDAC) in Lausanne, Switzerland, tapped childhood memories of playing with his father’s calculator. Those same recollections provided crucial insight into how to design for optimal learning: “I don’t expect kids to know what they’re doing by knocking on its surface.” Instead, Klouche says, “It’s a toy with which they should be able to slowly decipher its mysterious behavior.” The designer also stresses the importance of having to sit and listen to literally every numbered knock: “Having to wait for 72 knocks makes you really feel how 72 is bigger than 15, whereas visually it’s not obvious.”