I was sitting in bed & I kept hearing these banging noises in the house. I laid there for awhile, debating if I should call the police. I was sure I had a burglar in the house. The noise was so loud that I imagined she had broken into the apartment & she was in the process of stealing everything. The noise continued for about an minute before I realized it wasn’t a burglar, however the noises were coming from inside the walls. I imagined that I had large rats trying to eat through the walls, although I knew that wasn’t right either. I finally had to confess to myself that our noises were coming from the air duct. I didn’t believe what was wrong with the Heating & Air Conditioning system, however it was telling me that I had a definite problem. I called the Heating & Air Conditioning company the next day & I told them that the air duct was banging & I needed their assistance. The Heating & Air Conditioning serviceman showed up a couple of minutes later, & she went right to work. She told me that I was lucky our gas furnace hadn’t died on me. I hadn’t changed the air filters in a couple of months & they were clogged with dog hair. She said that the noise was coming from the gas furnace as it tried to send the heat through the house. I was hearing death throes coming out of our gas furnace. If it hadn’t been for our calling when I did, I would be purchasing a new gas furnace. As it was, I was going to need to purchase a new gas furnace in the near future because of our not doing our task.