[secondaryacct]

Or a 3 pixels camera whose pixel color changing is what matters :D

The only difference between a camera and a mic is the number or vibrating thing it cares about (mic only cares about the vibration of its single membrane, cameras create millions of membranes sensitive to photon vibration on a grid)

LIGO 3 interferometers care about the time-variation of the difference of distance measure in 3 groups of 2 mirrors. So it's more than a single mic, and it's a derivative of 2 distance measures, in time. It would be like a 3-pixel video, with white as a baseline for the 3 pixels, and it would varies towards green or blue depending of the negative or positive difference (random colors) between the mirror distances.

Or yeah, a 3 channel sound :S

[foo92691]

The microphone analogy is particularly apt, because the signals are also audio-frequency. You can listen to them. Sometimes in the control room we play the output on a loudspeaker. It can help in tuning the instrument (most of what you hear is noise).