Sandy Leon hit a double off the Green Monster ... and maybe scared someone inside it

One of the most iconic ballpark features in all of baseball is the Green Monster at Fenway Park and its manually-operated scoreboard housed at the base. That scoreboard can also get a bit noisy when a ball hits off it.
When Red Sox catcher Sandy Leon hit a double off the scoreboard in the fifth inning of Sunday's 5-2 win over the Blue Jays, we heard that the sound can be loud enough to inspire fright (as you can hear at around the :05 mark in the above video). 
It's possible that the scream came from someone inside the Green Monster. The clank of the ball off the scoreboard is plenty loud from the outside, but one can only imagine that is amplified greatly within the wall. Whether from inside or out, the reaction Leon's double produced is incredibly understandable.