The directions function a little bit like a game of Hot and Cold. If the belt vibrates near the belly, or front of the torso, then the soldier keeps going that way. If it starts vibrating on the side or to the back, the soldier turns until the vibration is back a the front again. There is also a visual display hooked up to the belt in case someone really needs to check what way they’re going
Still in an early prototyping phase, the belt carries no guarantee it will ever find a place on the waist of soldiers already loaded down with 60 pounds of gear. Since 1994, the Army has been trying to find the right mix of clothing, computers, and communications equipment through its Land Warrior program.
While the belt weighs less than a pound, “everything that gets onto a soldier’s attire has to earn its place,” Mortimer says. He anticipates commercial applications for hiking, navigation, or emergency response crews.
An Army news release about the new technology said soldiers were able to become proficient with the system and its signals within 10 to 15 minutes. Their stated goal of the project is to create a system that is "hands-free, eyes-free and mind-free.”
source: smithsonian.com by By Mary Beth Griggs