If you have a DACS at your disposal, you can convert the old sound files over to something that can be used on new ASTi systems. First you'll need to convert the .ASD to a .AU file. Go to the Soundfiles menu on the DACS, select a sound file and then press the F2 Key. This will bring up a new menu where you can select the option "convert to…". Make sure the new file name ends with the extension .au and press enter. The conversion status will be posted along the bottom of the screen. When complete, you'll have a new .au file located in your DACS directory.
AU files can be loaded into most sound file editors and manipulated easily. On ACE Studio, a copy of Audacity is included which allows you to upload a .au file and "Export As…" a new .WAV. Remember to set the sample rate to 48kHz, keep the file as mono, and select wav-16 PCM encoded as the type of WAV file. After doing all that you'll be able to use the sound file as you need and listen to the sweet sound of "Washington National Airport information, kilo…"