I just bought this game, and there's no dialogue sound whatsoever. I KNOW the entire dialogue isn't voiced (save for a few REALLY important conversations), but I'm getting nothing. The background music works fine, just no voices.

Do sound effects work (hitting enemies, for example)? And please state your OS when asking about technical issues, this can help find the answer faster.

There are a few things that can cause this that are not related to the game at all, one apparently being outdated audio drivers (oddly enough). Check your general audio settings, too; PS:T expects stereo sound, and may not be able to handle some of the other configurations properly.

The command/select responses from the characters may not always play, depending on the game settings, but Morte's very first dialogue line is voiced, and so is TNO's "Updated my journal" message (get used to it! :D), so you can use those to check if the speech sounds work.

I'm using Windows 10, and my drivers are up to date. I am not getting Morte's first dialogue, nor the constant TNO "Updated My Journal"

And I don't think sound effects work either.

My Sound card (I think) is a Sound Blaster ZX.