What is it called when there is a historical imprint on time? Ie: hearing sounds from years before.?

The other night my wife and I both heard what sounded like an old time radio broadcast for a split second, we both heard a male voice loud and clear. I remember reading about some men walking on the beach in normandy many years after WW2 and they swore they heard gunfire and stuff. Any idea what the technical term is and where I can find more info?