Since you claim they are fire & medic dispatches you can simply look up addresses on Google Maps and this should clue you in to who you're listening to. Shouldn't be that hard if you have a good copy
Bucks (or rather, one of the fire companies) used to have a repeater on that frequency (former East Band) that rebroadcasted the new East Band talkgroup, but I have not put a receiver on that frequency in a long time to see if it is still active.