There are a number of ATC programs available to flight simulation. One of the popular ones is Radar Contact, which was firstly released 21 years ago. Recently, its developers announced to give the program away for free from January 1st, this year. If you are not aware of it, you can get your copy from here.
ATC
72: Add Realism to ATC Communications
EditVoicepack is a simple tool that helps realize a more realistic ATC communication environment and allows to change the phraseology as well as airline callsigns, airports and aircraft types in FSX.
Current version available for FSX is 4.0.7.0 at the time of this post. Customized EditVoicepack files could be found in AVSim and FlightSim file libraries.
FS Times 