VBS2 has this feature
... The OP obviously was trying to be cute about the very real life and death roles our uniformed citizens face, but the truth is that with proper use the virtual combat arena the soldier increases his situational awareness by between 8 to 14% (Paul Roman, Associate Professor, Royal Military College of Canada). By training his "mental muscle memory" to be aware of sounds and reactions, his chance survival in a very hostile world increases measurably. Studies have shown substantial improvement in pass rates and higher standards throughout the organization. Not only do the teams learn to work together, but many of the usual variables that increase cost and create delays, are removed. Live exercises are expensive, difficult to coordinate and dependent upon weather, time of year and other external variables. The lesson is not to save half the training time in an evolution, it is to take that time to improve the overall standards of your force.
http://appliedstudiesgroup.com/ shows some numbers on training.
Also look at
http://battlegroundsims.com/ for some interesting information from various sources.