All the world's a stage

Does anyone have any experience running auditions in an open space?  I'm used to arriving within a certain time frame and being called into a room or aud. individually by a monitor to present a monologue.  Since we don't really have a reception area at our current space (we're rehearsing in a big common room at a church), I am concerned about the room getting too noisy, or other actors distracting the one trying to audition.  We all know how stressful auditions can be, and I hope I don't have to make it more so by having them audition in front of 40 people instead of 2!!

I'll be running these auditions for a Shakespeare in the Parks production in just a couple of weeks and wanted it to be as quick and painless for the actors as possible.

Any suggestions?