the voice work

Now I remember reading about the actors doing there own voices, but after I just recently bought this game (got it on sale new for $10, thank god!), I started thinking: these voice actors sound like them but something is off?

Is this because they just werent into it? Just doing it for contractual obligations? Granted I am only on like level two I believe SPOILER POSSIBLE: Where your in a facility on new vulcan and you face a gorn. So maybe the voice work gets better?