i just had this happen and responded to Jamrock990 in the http://www.gamesas.com/bgsforums/index.php?s=&showtopic=885108&view=findpost&p=15674166.
i made the Storms & Sound - Better Cities patch and i know everything was working with 0.9.7. after i upgraded to 0.9.8, the interior sounds would disappear after a couple seconds. reinstalling the All Natural Base.esm from 0.9.7 got everything working again. i did update obse from beta 4 to beta 6 at the same time so that is something to consider.
also, it happens in vanilla interiors (which my patch doesn't touch - the original Storms & Sound hits all the vanilla interiors). i don't understand the scripts so i can't help.
in game everything works with this setup:
obse beta6
storms & sound 3.0
storms & sound - better cities patch
all natural weather 0.9.7
better cities 4.5.0