Why no cloister bell in pandorica opens / big bang?

I really expected to hear the cloister bell in pandorica opens / big bang, and was puzzeled when it didn´t happen. I mean, the universe besides Earth ended. Can there be a bigger catastrophe? So why didn´t the bell ring. Thoughts?

 

Maybe the voice that said "silence will fall" overrode it.

 

^ It was Silenced.

 

Maybe only the Doctor can hear it. In the critical moments River is the only one in the TARDIS.

I think the more important thing is, why did River go through the whole Charade of going to Amy's house and looking at all the Roman stuff, when she knew full well Rory was her Dad, and had already seen him dressed as the Centurion?

 

Wasn't the TARDIS exploding at the time of the end of the universe? That might have affected the cloister bell's ability to emit sound.

Or, perhaps the Cloister Bell needed new batteries and the Doctor's been putting that off for awhile.

 

River hit the Mute button?

 

She would know where that was, bloody smart arse

 

Did she? Amy forgot him when he was erased from time, why wouldn't his daughter?

Of course, Moffat offered the more lazy explanation that she was just pretending to prevent spoilers.