I think you’ll get too many false alarms. Glass break detectors look for a very specific audio pattern for just this reason. But you could try one and see.
People do use them as a door knock detector, but with varying results. It depends very much on the acoustic properties of the particular door. For some people it works great, for others it never goes off, and still others get false alarms for everything from a truck going by to a kid running down the hallway.