I think a lot of the posts above are slightly unfair on the passengers who experienced and presumably reported this. I've sat with Mrs J-Class next to a very noisily leaking seal on an A320 window exit and the combination of weird sound effects - which gave the impression that something was wrong with the engine - and freezing air was causing anxiety to everyone sitting nearby. The captain came down to reassure us everything was OK, which was the right way to handle this kind of thing.
On a newish model such as the A380, with a recent history of near-disaster, I'm not at all surprised at the reaction.