I listen to 3 to 5 on a regular basis, and swtich on more if something good happens. I would guess that most people do a similar thing that I do: It is easy to pick out one scanner to focus on and ignore the others, but I sample the others for something out of the ordinary. I don't really listen to the words, I listen to voice patterns and emotion. Its hard to describe - it is sort of a 'Zen' thing. If you are not relaxed, it is difficult to do.