How are change-overs between regional air traffic patterns communicated?
There won't be any publicly available source for what you're looking for. Any information that you could get access to (as mentioned below) won't be reliable enough to predict when the runway changes will occur. The initial coordination always happen over secured phone lines between the controllers at the radar approach/center facilities and towers. There is no way you can hear this. 

Each airports ATIS (Automated Terminal Information Service) (https://en.wikipedia.org/wiki/Automatic_terminal_information_service) will be reporting what the runway(s) in use are - but this won't actually change until the runway change becomes active, maybe 5 minutes before. I suppose it would be possible to monitor this, probably via LiveATC (or setting up your own equivalent). You could somehow monitor or export this information and listen for key words to trigger your whatever-you're-using-to-shut-off-your-"sensitive equpiment" - but I think you'd get a lot of false positives. On the same note, you could also hear controllers making their initial calls to pilots advising them of the impending runway change (probably on arrival feeder sectors of ATC or the center descent clearances). 

I don't think either of these methods are reliable enough for what you're looking to do. You may consider moving your "sensitive equipment" to somewhere not near an airport.