In this photo taken June 23, 2010, Master Sgt. Todd Nelson sits for Dr. Joe Villalobos as he makes adjustments to a prosthetics ear at Wilford Hall Medical Center in San Antonio, Texas. Nelson was injured in 2007 by an explosion while serving in Afghanistan. (AP Photo/Eric Gay)

Photo by: Eric Gay

In this photo taken June 23, 2010, Master Sgt. Todd Nelson sits for Dr. Joe Villalobos as he makes adjustments to a prosthetics ear at Wilford Hall Medical Center in San Antonio, Texas. Nelson was injured in 2007 by an explosion while serving in Afghanistan. (AP Photo/Eric Gay)