A few days ago I was up in my bedroom on the computer working and watching a movie (I have two monitors so I work in one and watch a movie in the other). My dog was laying on the bed behind me and my two younger boys were downstairs playing. All of a sudden, I heard an unfamiliar child's voice. I paused the movie and listened. I heard nothing but my boys. I assumed it was my imagination or something and went back to work. About a minute or two later I heard it again. I turned to hear it better and my dog even perked up and stared at the door. I heard it again and clearly my dog did too because he took off out of the room barking. I thought maybe a neighbor came to the door and my boys answered it. Nope. They were playing quietly in the living room.
The next morning, my daughter was about to head out the door for school and all of a sudden turned and asked me if one of her brothers was downstairs in the office. I told her no, that he wasn't even awake yet. She got a puzzled look on her face and said she just heard heavy breathing coming from the little hallway area that leads to the office. Our house is three levels and if you stand at the front door there are stairs that go down to the office and stairs that go up onto the main floor. That is where she was standing when she heard it.