I want to know if the gog version of Wing Commander has any voices or alternate bgm like the Sega CD version did.

No voiceovers... But what I would do for Activision to allow modders to use the sourcecode and add the Sega voices to patch the game! I'd pay again if Activision would legally 'sell' such a version of the game!

Only the Sega CD version & the 3DO version (Super Wing Commander.) had voice acting. As far as I know there's no patch to add in either to the Good Old Games version of the game. And even if you could keep in mind that since those two versions are voiced you can't name your character which greatly takes away from the dialog in my experience.

- Ryan Paul Fialcowitz

In theory, unless one drastically changed engine of the dos/windows releases, the name interface in thr engine should still exist even if you put voices into it. Thr only difference is actors would ocassionally call him hotshot while the subtitles would say whatever the player had typed in the name interface.

The KIlrathi Saga versions still had the naming interface but had Blair and Maverick set to default.