Different sounds depending on location in a room

Hi !

I'm looking for a way to transmit different sounds to multiple wireless headphones depending on their location in an exhibition. For example : sound1 in the right corner, when the person moves to the left corner of the room he gets sound2 and so one.
So max should know where which headphone is in order to send the right sound...

The only solution I found until here is the use of short distance fm transmitters in the room, all tuned to the same frequency, and then Headphones with FM receivers which would get the source they're the closer to. But it I'm afraid this might sound a bit sh....y

Any idea would be welcome ! Thanks a lot !