Thanks for playing! There's an additional map file included with the game that has a bunch of warehouse locations and the associated code to escape it. So by listening to the sounds around you (and focusing in using the "F" key), you can figure out where you've been trapped. If you hear a train behind you, then you can check the map for all the warehouses that are in front of the train track, then listening to other sounds can help you pinpoint the correct warehouse.
But thanks for giving it a shot, I really appreciate it!