Voice lines.

I have never had an issue with the sound affecting game play, that I am aware of.  I have the full effect of Asteroid Chase music during space battles, the Duel of the Fates when facing Maul, the score of Vader rising and the mechanical breath sounds as the table rises, 3PO fretting (actually talking), the full Mando score.  The hum of the lightsabers and telephone pole guide wire reverb of the baster bolts, makes the game.  You can hear the AT-AT walking and shooting when Veers and Col Strack attack.  CG and LucasArts put all the Star Was sounds into the game, which I have told them when they used to do the big meetings with the public, that is what makes Star Wars, John Williams score and the sounds Ben Burt made throughout his career to make the galaxy come alive.