"Dancer"

is called an interactive robot whose speciality is to listen to sound (via microphones), amplifies it (via audio compressor) and the sound is then passed (via transmitter) back to the stationary sound system (in the space) - that closes the feedback loop.

The result is a microphony that changes as the Dancer changes its position. The robot moves like a gyro - in the manner that the received sound (via two microphones) gets compared in volume. The change in "left" or "right" volume changes the position of the metal weight - therefore changing the balance of the upper (nonmoving) part. The bottom halfsphere remains rotating - as a gyro.

The secret is that the upper part must be relatively fixed (in comparison to the lower part). This has so far been achieved by the inclusion of a "tail". In future the tail will fall off and another gyroscope will be added to the upper part.

The homepage of this project is http://www.3via.org/index.php?htm=plesalec