Ok this is weird. We have multiple set top boxes in out home connected to Cablevision. I was watching NBC on the downstairs TV and my wife was watching the same channel upstairs. She called down that she was hearing my TV then hearing the same thing upstairs a couple of seconds later. I had her turn the volume up on the upstairs TV and I listened to my TV and muted it. Sure enough, I heard the same phrase repeated from upstairs.

Both set top boxes are diigital TV, but its weird that they would be out of sync. Anyone else experience this?

Scott do you have, by chance, a spiral staircase ? Just joking, thought maybe it was taking the sound time to come down the stairs!! Seriously, I have no idea why.