The customer called back weeks later and the chirping was back and more frequently.. I was able to get there and troubleshoot it. I turns out i traced it back to one bogan self amplified paging speaker that was mounted outside, all the connections were done on the exterior of the building and just had tape wrapped around them. the wires were bare copper and had green corrosion really bad on them, as soon as i touched the wire it denigrated and the noise went away. It was on the power side, so it just had low voltage or not constant contact.... i pulled the speaker pigtail inside and re-spliced the wire and the speaker still worked no noise. it make a small chirp when i hooked the power up, which seems normal and is probably the sound i was hearing, just over and over with the bad wire.

i just thought that was interesting that that one speaker made the whole facility have a chirping noise.

Dave