Situation: I am facing two trash cans and there is a door on my right.
Alternative situations: Just entered a room through a door in my five o'clock direction and threw a food waste into the can in front of me, seeing that another thrash can in my one o'clock direction was already full. I am standing in front of the door behind me and reading the posters on the wall in front of me.
Question: What can I hear behind me that is moving paper?