Sabai, My understanding is different. I understand the Monoliths are just extra large peas, but perhaps I am wrong.
As for what exactly the PEAs do, its a little hard to properly articulate. I think RAks description above captures it. When you find them turned off, you know something is wrong, and when you turn them back on, you find things turned to what somehow just sounds right.
They take a while to work. When I got the first one, I put it in place and turned it on. Didn't hear much to get excited about. I took the dog for a walk, came back and it was OMG, what happened? I proceeded to add additional peas one at a time. Three seems to do it for me. My peas aren't going anywhere.