The audio file posted here contains transmissions between the aircraft and Washington (KIAD). The diversion occurred approximately 3 hours into the flight when the aircraft was over the Atlantic, north east of Bermuda. Flightradar24 tracking the flight shows a 200kts drop in speed at that time.
Although it seems no emergency was called, the controller mentions that a fire truck is in attendance on the ramp at Washington.
Is it possible/likely that the LiveATC archives could include communications from the area where the aircraft turned back to the USA?
http://www.flightradar24.com/data/flights/ua142/#82d22f8
