Voice

     Again a voice out of nowhere. I was at the computer in the library and my dog was lying on a rug between the library doorway into the diningroom and the library doorway into the den. My wife had taken some items into her shop in town several miles away. Other than my neighbor mowing his lawn, the area was very quiet. Had I wanted total quiet, I'd only needed to close the den window. Both the dog and I heard my name called, once, in a normal tone, coming from the diningroom. Thinking my wife had arrived home and was telling me as much, I answered. The dog immediately reacted to the "voice", his head coming up and looking into the diningroom. I got no answer, so I got up and followed my dog into the diningroom. There was no one there. My wife's car was not in the driveway. We both heard the "voice" and we both reacted to it. But what was it?