The Infinite Resonance theory states that any sound made does not stop, but just becomes more and more muddled and intertwined with other sounds, echoing on forever until they become indistingushable from the white noise. Following this theory, the moving speeches of Julius Caesar and Abraham Lincoln could still be faintly heard if we had instruments sensitive enough to detect them.
It's not that far a stretch of reasoning that sounds (and perhaps sights and other perceptions) of times gone by and times to come are floating around above and below the plane of what we consider conciousness.
Put that in your pipe and smoke it, eh?!?