Two Owls - Stereo

Was up late tonight and at about 12:50AM two owls perched just outside my residence and began having a protracted conversation. I ran outside with my H4N and started recording without really checking the levels and fidgeted with it a bit then set it down and walked away; eventually they started really getting into it (toward the end) and produced some throaty sounds I hadn't heard before. I'm not able to identify their species as I couldn't see them, but I suspect Barred Owl as over the Summer I had found a feather of a Barred Owl outside in front of where I live. I would really like to know what kind of behaviour is on display here as this is the fourth or fifth time they've done this this year.