As she strained to be heard above the sounds of simulated gunfire just yards away, Staff Sgt. Brooke Green talked about how different this all was from her normal duties at the Natick Soldier Systems Center.

"You don't realize the little intricacies, the fine-tuning, the teamwork," said Green, who is with the U.S. Army Research Institute of Environmental Medicine. "I think it's just that total awareness of every little movement, every little corner."

Green experienced that heightened awareness Sept. 17 at the Fort Devens training area, where dozens of Soldiers from USARIEM and Headquarters Research and Development Detachment underwent military operations in urban terrain (MOUT) training.

"It's using all your senses at once - hearing where it's coming from, accounting for the movement, seeing the people in our uniforms, seeing the people in the (opposing force) uniforms, being able to take it all in (at) such a rapid speed. It's hard to maintain that ... quickness."

Green and the other NSSC Soldiers worked to hone that edge as teams in an urban environment with room-clearing and squad-movement exercises at Devens while carrying rifles. By the end of the day, they were assaulting a building against opposing forces to look for hostages and weapons caches.

"I was able to link up with the 804th Medical (Brigade) over here, and they were able to give us rifles," said Sgt. Jay O'Hara of USARIEM, who led the training. "Everyone's got a weapon. Everyone gets to actually feel the weight and ... do the actual training."

Sergeant First Class Raymond Persaud, the USARIEM first sergeant, instructed the Soldiers on handling the weapons.

"From now on, everyone with weapons at ready," Persaud said. "Consider this a hostile area. Weapons are always at the low ready."

Persaud pointed out that NSSC troops spend every Friday afternoon on soldiering skills and that once a month, an entire day is spent on related training.

"It's real easy to get the ranges," Persaud said. "Devens has been real helpful."

Persaud said that MOUT skills tend to erode without practice in about six months.

"You have to learn how to work as a team," Persaud said. "So they need to know their sector when they get in (the rooms) and take the enemy - and only the enemy - out."

"It's basic refresher-type skills," said Capt. John Lavoie USARIEM detachment commander. "Some of these things these Soldiers haven't seen for a long time, so it's a good refresher."