Total time - approx 30 minutes.

So, long story short... Something happened with the furnace that caused it to utter a rather odd tone at loud enough that it caused distraction every 30 minutes or so. I'm thinking that it's a bit like resonance or something like that because the furnace person came by a second time to diagnose it and they couldn't find anything obviously wrong with the sound. And to be fair it's not super loud but it's at just that "right" level of volume to be there and not so soft that I can dismiss it. (it's really fucking odd too... like, the entire house had turned into a sort of pipe-organ where the ducts and the halls and all that served up the perfect resonance to amplify it when you're in certain spots in the house... Guess where one of those spots was? yep. the desk.)

so, this is a bit of a "vent" post (yar, har harr) in some sense.

Yeah, it's still there but I figured out that seriously loosening the panels on the return grating and the furnace itself may have disrupted the air flow enough to reduce the volume to a tolerable level. It's still there but it's now possible to ignore it.