Structural feedback
Compare the two photos below:

Sketch before construction	Finished Product

As you can see, the finished product bears a remarkable resemblance to the original sketch. This I attribute to Shannon’s construction prowess. The loops of audio cable and rope provide a sense of recursive adjustment and feedback while the equilateral nature of the teepee naturally lends itself to loopy thoughts.

Social and Behavioral feedback

Interestingly, our test audiences have established themselves in semi-circles around the piece. By yelling at the piece, or by having a conversations with each other, the viewers can alter the behavior of the teepee as it tries to maintain a constant sound level. An interesting result involves yelling into the suspended microphone and having your voice trigger a feedback loop. The leisurely speed of the movement also seems organic. The microphone is very responsive, but “heavy”.

Technical details
Many of the behavioral responses are a result of mapping a non-linear input onto a linear output. Feedback is a non-linear function of the distance from microphone to speaker, and other environmental conditions while the movment of the microphone is a linear constant.

The BX-24 microcontroller is running this code. It is taking samples of the ambient noise level using a small electret microphone running through an LM386 amplifier. The ambient sound level is extremely “bouncy”, so we are taking the standard deviation of the noise levels as our input, not the noise levels themselves. This works famously. The BX-24 then controls a home-made H-Bridge to move a motor forward or backward. Forward motion raises the microphone via pulleys to lower the sound level, and backward – as you’d expect – does the opposite.

Description

Ever raised your voice in a crowded room? Ever whispered in an an quiet space? The Sound Governor explores these unconscious social habits in several contexts. As an artificially intelligent being, its one life goal is to maintain a constant level of ambient noise in the room. Like any living creature, it is in a constant state of flux as it struggles to maintain osmotic equilibrium with the world. To do so, it raises or lowers a microphone suspended above a speaker. This amplifies or attenuates its auditory feedback. The more conversation that is taking place in the room, the higher up the microphone. The quieter the room, the lower the microphone. In its physical form, this sculpture plays with the meaning of feedback and its importance in living systems by using cables and ropes that interconnect the support structure, the microphone, the speaker, and the viewer in an interactive symbiotic relationship.

User Scenario

A single viewer enters the room and hears a loud low frequency hum emanating from the piece. She sees the microphone raising and lowering itself in a seemingly “living” manner as the Sound Governor tries to maintain equilibrium with the world and its own bodily functions. As more people fill in the room, the hum subsides as the microphone settles up to the top in a hesitant manner. As people leave one by one, the microphone adjusts itself continually until it is again low above the speaker and producing a loud hum when nobody is around.

Technical Details

The technical details are very simple. Four small electret microphones at the base of the piece feed the ambient noise level into a microcontroller. The microcontroller controls a motor in response that raises or lowers the microphone via pulleys. The microphone is suspended above a large speaker and amplifier. The support structure is in the shape of a wooden teepee. The electronics are covered by a burlap sac.

Here are some ideas Shannon Bain and I have been throwing around for our final project. We hope to complete several of them with a common thread (perhaps all involving a concrete platform/pedestal)

locker worm
an x-y plane of buzzing motors inside a row of lockers with two locks as the controls – like a big noisy Etch-a-Sketch.

sound governor
speaker with microphone suspended above. microphone lowers to increase ambient sound level. display strives to maintain a constant decibel level in the room.

comfort zone
BMW seat strapped to a cement base with hydraulic pumps. When the ambient termperature hits room temperature, the pumps go crazy.

fascist factory
immersive environment which presents a viewer with video and audio material. The installation tries to effect changes in the affect of the subject. Using an AI learning algorithm (hill climbing, a*, neural net, or maybe even minimax) to measure subject’s responsiveness to the tactics used.

rock show
lights and explosions and a red mop of hair representing Tawny Kitane.

cellular automata locker
evolving mobile cellular automata. dual worm system. worms create buzz in locker door.

big dumb accelerometer
a big cute and dumb barebones “thing” that somehow evokes empathy based on its appearance. Inside it is a cheap home-made accelerometer (4 hall-effect sensors around a magnet with a little bit of play). Also has a voice chip, some IR proximity sensors, and a source of amplification (either via radio, or a just a built-in speaker). The big dumb accelerometer is taken to the top of a building (preferably Bobst library) and thrown off the edge. Just before it crashes on the ground, it cries out, “But wait!…”