I too, have lost my ATC voices, along with my own pilot voice. I can open the ATC window, click the ATIS link and no voice or text appears onscreen. If I click "Contact Tower or Ground", the same things happens, no voice or text. As others have said, the routine of going through clearance and so on works, just without voice or text. Having followed all advice I have read here, I still have no ATC voices. Checking in Settings and General, "Use Pilot voice" is checked BUT.... there are no pilot voices available! That's interesting because I ran a new installation of FSX and a repair of Acceleration and still there are no voices available. On the good side, my Airbus has reappeared, having been missing because its .cfg file had somehow disappeared.
I am running Windows XP Pro on my computer and have no idea why the ATC voices just suddenly stopped. Checking with Windows Explorer, I notice that there is an ATC folder within the FSX/Sounds folder but I am not sure if all its files are there.
I think I have tried everything and cannot understand why there are no pilot voices available. Any ideas?