Mood: Ready to parry. Snap-hiss. It is arguably the most recognized sound effect in cinema history. Ben Burtt, the genius sound designer for Star Wars, created it by recording the idle motor of an old movie projector and mixing it with the electromagnetic hum of a television picture tube. To most people, that sound signifies "Cool Sci-Fi Sword." To me, a blind man living in a world of silent threats, that sound signifies something else entirely. It signifies Hope. Here is the thing about weapons in the real world: they are terrifyingly quiet. A gun is just a cold piece...