Mysterious sound randomly plays every time I play...?

[persian.bobby]

Hey guys, I've been getting this sound:
http://www.youtube.com/watch?v=gw2g_IKs7oQ :deal:

(The one played at 00:10)
Nearly every time I play Sims 3, it doesn't bother me, fully, but not knowing why it keeps playing feels weird. Does any of you know what is it about? Thanks! And sorry if wrong category! :rolleyes:

[simsample]

It's just a notification for one of the other sims in your world; it happens in my game too. I think it must be an error with the way they programmed the sounds for the game.