Who knew?..
In order to get the hyper-realism that director John McTiernan was looking for, the blanks used in the guns in the movie were modified to be extra loud. In one scene, Willis shoots a terrorist through a table, which put the action star in extremely close proximity to the gun—and caused permanent hearing loss. He referenced the injury in a 2007 interview with The Guardian. When they asked Willis his most unappealing habit, he replied that, “Due to an accident on the first Die Hard, I suffer two-thirds partial hearing loss in my left ear and have a tendency to say, ‘Whaaa?’”
