Combat Awareness( Player's Handbook II, p. 86)
[Combat Form, Fighter Bonus Feat]
When you maintain your combat focus, you have an uncanny ability to sense the ebb and fl ow of your opponents' vitality. As you attain greater mastery of this fighting style, you learn to sense a foe's presence even with your eyes closed.
While maintaining your combat focus, you learn the current hit point total of each adjacent opponent and ally. If you have three or more combat form feats, you gain blindsight out to 5 feet.
A fighter can select Combat Awareness as one of his fighter bonus feats.