Ever wondered how well playing Call of Duty at maximum volume mimics a real combat experience? Researchers at the Missouri University of Science and Technology must have asked a similar question, because they've built a 64-speaker surround-sound audio battlefield designed to train new troops. The system reproduces screaming fighter jets, rumbling tanks, and persistent gunfire -- all the better to accommodate recruits to the overwhelming, disorienting cacophony of warfare. Veterans say even with the four large 20-hertz subwoofers, it's nowhere near the real thing: combat volume is 25 percent louder than the average rock concert, at levels that can cause permanent hearing loss.
