It always plays the gate fully closed sound effect, even if you're not in the room; in all levels.
It's just that the demo level has no music, so it's easier to hear.
Maybe not remove the loose tile (see here)?
Hm, I don't see any new buttons, and I'm logged in and did a hard reload of the page (Ctrl+Shift+r using Firefox).
That reminds me of:
Going by the confused smilies, you prefer (and/or are used to) more traditional gender divisions/attitudes?