Yes, adding noise will be unavoidable, but not broadcasting an ssid means unsuspecting people won't try and connect to these pseudo AP's.
To cut down on the interference caused by the added radio noise one could either hardwire all the pseudo ap's to use the same channel, effectively blocking anyone from using it, or have each ap actively scan and switch to the least used channel at a set interval.
WiFi APs with hidden ESSIDs still send beacons, but don't include the ESSID. This means that they'll obviously add radio noise.