I don't have any issues with the steam version, but try this fix.
Go into your steam library, right click swbf2, click properties and then click the tab "local files"
Try the "verify integrity of game files..." button. That should analyze all of the contents and fix errors that might have happened when downloading. Something maybe got corrupted somehow.
I've had to do that a few times for counter-strike, sometimes my game will crash or give me errors saying I can't play competitive matches but that's fixed it I think every time.
edit: if you could record the audio before you fix it, I'd love to hear it