The X32 is a series of audio mixing consoles[1] to combine the signals from multiple microphones and/or musical instruments to a venue's speakers or to a recording/streaming apparatus.

In this case, there are multiple points of interest on the stage which are sometimes used, and sometimes not. When an area of the stage is unused, the microphone(s) at that location are manually muted to eliminate unwanted noise. The remaining unmuted microphone is at a location of interest, which is also the logical thing for a motorized camera to point toward and zoom onto at that moment.

This project uses the muted/unmuted states of microphones as a cue for camera movement, although it takes some upfront work to set it up. It also could cause trouble for looser or more improvisational shows where such rigidity might actually get in the way.

[1]: https://www.behringer.com/series.html?category=R-BEHRINGER-X...