Hall of Infinite Doors

You raise a fist and gently tap on the door. Perhaps you were a little too quiet as no one answers. Gathering up more courage you knock louder and say, "Hello?"

"Yes..?" A muffled voice answers from the other side. "Co... He... Or... En."

"Sorry, can you repeat that?" You ask with a hand over your ear.

"Come in, the door is open."