I've sent an issue report on the Lionhead forums, as many others did as well. Hopefully the developers will find out what the cause of this issue is, as well as release a patch to fix said issue. And sadly enough, this glitch is more than "game-breaking" enough (personally) to not play Fable 3 until it's fixed. I'm also certainly not in the mood to start another game just to find out that it'll happen at random once more.
That said, I think it's also good to mention that my "glitch" is not just audio; interaction with Jasper in overall is inapplicable. The inline fast travelling in the sanctuary seems inapplicable, too.