Mumbling again

Once again I have had mumbling. It occurred a couple nights ago, I have just gotten time to report on it. My dog and I had just turned in for the night. The mumbling started while I was in bed reading. Shadow, my dog, did not seem to notice it. On the other hand I fear my old pup is getting hard of hearing. She recently turned 12 and I've surprised her a couple of times while coming up the stairs. Nothing use to ever get past her hearing. Anyway the mumbling in the bedroom was typical. A male voice this time was in the lead with other whispering about. Never loud enough to make out what is being discussed. I was tired but I got up to see if I could determine where the mumbling was originating. It sounded just about the same in every upstairs room. Like I said, I was tired so I didn't go downstairs. Finally, getting a bit perturbed of it I said, "Dang it, speak up so I can understand you or shut up." It was possibly coincidence but the mumbling faded away at about that point. Shadow had followed me about the upstairs but I really think she was just curious about my movements rather than because she heard anything. We then turned in for the night. I really wish I could tell what the mumbling is all about. It's frustrating. Did I mention that I forgot about the spy camera and left it running until the batteries gave out? When I, by chance, saw it and took it down it had shot 660 pictures. I have no idea what could have activated it so much and so far I haven't had time to go over them. I had the camera set up to shoot across the front of the parlor. I changed the batteries and set the camera up again to shoot the front stairway. The next day I had 60 shots. I still haven't found the time to see if anything interesting is on any of them. They did work I did check them on my tiny monitor to make sure they at least worked. The wife had been sick; maybe if we can ever get her straightened out I'll try to see if I got anything.