The sound is part of a line of dialogue said by Ullman. "the idea of st" The full line is, "Obviously some people can be put off with the idea of staying alone in a place where something like that actually happened."
I hope you all appreciate that in this scene, just after Jack is told about the Overlook's history, the walls behind him start to pulsate. Watch the interview scene, you'll see all kinds of weird stuff. Search "The Shining" here for the rest of my gifs from the movie. Happy Halloween!
I think subtlety is lost in today's fast food world, so unlike my last The Shining gif, I'll tell you the secret up front because nobody got the last answer right. Ullman is sitting perfectly still, the room is pulsating. Don't tell me it's a flaw in the film. The shot just before this has Jack sitting perfectly still and the room around him is very stable. This room appears to be having a small earthquake, or maybe the hotel is alive and breathing. Also, the desk is on it's very own "Dutch Angle", because it's not level, but the table behind Ullman is level and so is the window. So, the desk is out of whack.
okay, I win. If you notice the man pushing the luggage cart, there must be a time portal behind the column because the reappearance o the cart from behind the column is noticeably delayed. Kubrick was messing with your mind to disorient you. Like in a fun house.