I've noticed some strange echo effects before. I would try to find the source of the original sound, assuming it is being carried over from somewhere else.
There is no "would of", "should of" or "could of".
Honestly? Nothing. It's happened before. It'll happen again. All that matters is if you can distinguish what's real from what's in your head, which is generally pretty easy.
PSN/Steam: HaVeNII7
Current Events» You start to hear strange whispering coming from the walls every night