This is an interesting question. Yes, they DO yell out random instructions, but they are also accompanied by the flashing buttons. For example, Hondo may yell out "left pilot, hit the brakes" but simultaneously a button will light up and flash where the left pilot is. Basically, the ride boils down to "hit whatever button is surrounded by a green light or any button or switch that flashes, at the time it is actively flashing." The pilots just have the additional job to try to not crash AND follow the train. I suspect the flashing lights are the substitute for the spoken instructions since people may not understand English well in addition to hearing issues that guests may have. Right before you board, the CM will tell you "hit the flashing buttons." As long as you relay that to your wife, she will be fine.