This morning I awoke from my fitful sleep and, after clearing my head, immediately began playing back the audio recording made during the night. It was mostly the usual sounds of slumber-- the bed creaking, breathing, etc. This in fact went on for hours. I listened, my attention drifting as I went about the start of my day. Then, about four and a half hours in (making the time roughly half past three), an few odd sounds joined the normal ones.
I have uploaded the audio so that you can listen as well, followed by a short interpretation of what I think we are hearing in the recording.