John Farmer has posted an audio file of a Arlington County Police Dispatch on 9/11. Farmer explained to me that the availability of this recording has been restricted:
It has always been available if someone wants to go [to the Arlington County Emergency Communications Center] and listen to it and do a transcript by hand (no recording permitted)... I can’t say they have never released it beyond the building before... I acquired it through the AC Police department after a great deal of advance work.