I am surprised that no one has mentioned this before.
Or perhaps, someone has mentioned it and I haven't read it.
...or maybe, for some strange reason, I forgot :)
But, is there any place in the five episodes of Series 7 that we have seen so far, that there may have been Silence? Is there any scenes where people look at something suddenly and then turn away? Any scenes where people act like they've been told/suggested something? Any purring noises in the background?
...okay, start rewatching in a paranoid frenzy now! :)