Some good points here. In my basement shop, my biggest surprise would be a spousal visit. I have a sometimes remembered arrangement for her to call my name several times as she descends the stairs.

John, I'm not so sure I would want my door dead bolted. I think I want to be able to exit easily and quickly if needed and I want to be accessible if an emergency arises. Locked doors could complicate emergency egress or block someone getting to me if I'm injured. Perhaps a doorbell loud enough to hear over power equipment would be an alternate solution?