Okay i don't know if anybody has noticed this yet or anything but basicly when you are the doctor you spawn with the wonder gun peice that you give him in call of the dead.
This is located near your frag grenades

Also when i pak-a-punched with the doctor he said that he should go around hitting the symbols really hard..
Now i have found out what symbols make certain noises and what symbols make an occuring ringing noise that never goes away untill you hit a different type of symbol.

The symbols make noises sort of like a ray gun and there is four of these

There is also four other symbols that just make the noise and then ringing happens after and if you hit all four then the ringing is quite loud

If anybody can help me out with undersrtanding what these do? and if they are part of this annoying easter egg