The most disturbing environment in Halo: Reach is one you'll never find. It's stark and absurd: a cavernous stone passage that seems to extend forever, flanked on one side with brackish green water, populated with disembodied air-lock doors, grounded aircraft and hot-pink bands running across the floor, walls and ceiling.
In his combined office and recording studio in Bungie's Kirkland, Wash., offices, Audio Director Marty O'Donnell taps at a keyboard and, in Matrix-esque fashion, a purple alien attack craft dumps into the virtual space. He tosses a grenade at the Banshee and, as he explains that there are 13 separate sound effects triggered here, the explosion bangs against the craft, which rocks in place, sheds fuselage and sizzles. Then, all 13 effects roll down across the computer monitor as individual text markers