We currently offer a massive range of downloads for FSX, as well as older flight simulator add-ons for the ever-popular FS2004, FS2002, CFS3 and now becoming ever popular with dediced virtual aviators is Laminar Research's X-Plane series.
I have tried to get help for this once before without much luck, so decided to try again. I am trying to run Flight Simulator X on Windows Vista Home Premium. When I run "Missions", I do not get the voices during the briefings. And when I run "Lessons", I do not get the instructors voices. The introductory music plays fine, and I can turn it either on or ****. And to answer the first question I got last time, yes I have the "settings" set correctly.
As you say, you may have already tried this but make sure you have the 'Voice' and 'Effects' sounds played through your headset/speakers.
It is possible to have them played through different sound devices and sometimes I forget to reset one or the other if I have changed my configuration, e.g. if I have set the Voice to play through my headset and I have disconnected my headset for whatever reason, then the voice does not play through the speakers.