I have a weird problem with my Macbook. My ESC key doesn't respond by itself. It only works if I use Fn+ESC, and combination like optioncommandESC and command+esc also work. But ESC by itself fails to respond.
There isn't any shortcut linked to the ESC key and the speech recognition is switched off, i even changed the listening key and that did not work either. And even when I change the keyboard profile the problem persists.
Another weird thing is when I have the keyboard viewer open and I click on the top so it is focused on the keyboard viewer the esc key responds, but once I click on another program the esc key only works with Fn key.
Read some other posts, and when I undid the check I had under Settings, Speech, and "recognize speech..." it was magical! I think I checked the box when I was installing MacDictate. Glad it is now fixed.