One of my projects years ago was designing and installing an system for recording training exercises in a nuke plant control room. There is a lot of machine and mechanical equipment noise in the room, the mics had to be out of the way and people were facing all different directions, but they wanted to hear everything said in the recording. This was in the days before DSP systems or computer based, real time noise cancellation so careful mic selection and placement along with an IRP System 41 rack full of parametric filter cards was what we came up with. The resulting signal sounded like crap, but was intelligible.