You'll notice the doors are wedged, with overlapping, key-like
sections into which the doors settle. When they close, the sound you hear
is the door sealing shut, and pins extruding into place to keep the door
shut (in the key-wedges). That's also why they slide down, rather than
part in the middle; it's totally airtight in case of pressure falls. So
yes, we *did* think of it, and took care of it, by thinking of a new way
to do the doors.