Apparently the most shocking aspect of the battlefield environment for raw recruits is actually the sonic intensity of the gunshots and explosions. The sound pressure level and intensity is enough to render soldiers dysfunctional on first combat. To train people for the contemporary combat situation Professor Steve Grant of Missouri University has created a serious sound system that is designed to give troops some idea of what they’re in for before the actual truamatic experience.
It comprises 64 speakers that can fire in small groups to aim sounds at a specific three-dimensional location. The low end is powered by four subwoofers, and it’s all hooked up to a truss that measures 12 meters by 6 meters by 5 meters. Inside that truss, a small unit has enough space to allow a soldier perform maneuvers in full gear, complete with an appropriate soundtrack.
Health and safety regulations limit the system to 100dB for experiments on students but should it become adopted by the US army as a training rig expect 125dB plus as Kalashnikovs, mortar rounds, and jet aircraft are simulated.(not quite as loud as a Lygon St car stereo system then ...)
To achieve the full shock and awe Professor Grant is utilising the following kit:

RME M-32 AD (2) used for the 64 channels of digital-to-analog conversion
MPS-488E (6) power supplies for the Meyer MM-4XP’s
RME Micstacy (1) preamp and analog-to-digital conversion for microphones (8 channels)
RME ADI-648 (1) to be enacted
RME Octamic II (7) to be enacted
Mackie HR824 (12) main speakers
Meyer MM-4XP (44) satellite speakers
M-Audio SBX10 (4) subwoofers

Associated Press May 7th 2011.