Although I have not personally tested them as I don’t have Prepar3D or PRO-ATC-X it seems that some users have had success with using them. Check out this thread on the PRO-ATC-X forums.
http://www.pointsoftware.de/proatcxforum/forum/index.php/topic,2991.msg15074.html#msg15074
It may be necessary to convert the collection from .mp3 format to .wav format using any number of audio file conversion utilities.
