A small horde of miniature electromechanical noise-making devices are arranged in a dark space. Most machines are completely autonomous, with their own power-supply, sound actuator, and timing logic. A few of the devices are networked, with a master device switching power to a pair slave machines.
The machines are designed with all components effectively identical, with the exception of sound actuator and timing duration. A simple 555-based circuit is used for timing, and each device has a set actuation period, determined by a timing capacitor. The timing capacitance is limited to a handful of increments, so that although timing is varied among the machines, actuation periods would recur.
For sound production, the machines rely on two different sizes of solenoids, which produce tapping sounds, and two different types of vibrator motors, which are responsible for rasping and more-sustained repeating rolls.
Each machine relies on a substrate, a feature of its location, for its noise-making. That is, although each machine is equipped with a mechanical actuator, it has no resonant body of its own. Thus, the devices must be paired with elements of their environment to actually produce sounds of appreciable volume. In this case, wooden pedestals of varied size, some with large and small cavities, are distributed in the space, with the parasitic instruments placed inside or on top of them.
The exhibition space is cloaked in darkness, and the machines remain invisible except for subdued illumination provided by tiny LED’s which flicker briefly during activation. See video