Ziru Sirka.
Thing is, we'd have a bloody hard time detecting ourselves right now from Alpha C, let alone Barnards. While we can detect a cell phone at jupiter (and Voyager 1&2, and Pioneer 10, out past the heliopause), we're talking
Pioneer 10 roughly: 1.4960E11 x 90
Alpha Centauri: 9.4607E15m x 4.26
269402 times as far... or 1/(7.257E10) the signal strength.
one seven-billionth the signal.
Really, unless one is actively trying to signal, the odds are you're not putting enough signal on target to matter.
Oh, and there is this nasty radio static everywhere... If your signal is significantly below (ISTR 1/10th) you can't send messages reliably, and below that is a detectability threshold (which ISTR is about 1% of white noise), and is what SETI is trying for... Just finding that needle using the biggest antennae they can find, with some of the most sensitive detectors money can buy.
In other words, Fermi's Paradox is pretty much a non-issue... unless they are spreading out, looking.