Hear The Unseen( Complete Adventurer, p. 110)
Your sense of hearing is so acute that you can partially pinpoint an opponent's location by sound, allowing you to strike even if the opponent is concealed or displaced.
As a move action that does not provoke attacks of opportunity, you can attempt a DC 25 Listen check. If successful, you can pinpoint the location of all foes within 30 feet, as long as you have line of effect to them. This benefit does not eliminate the normal miss chance for fighting foes with concealment, but it ensures that you can target the correct square with your attacks. If you are deafened or within an area of silence, you can't use this feat. If an invisible or hidden opponent is attempting to move silently, your Listen check is opposed by your opponent's Move Silently check, but your opponent gains a +15 bonus on this check. This feat does not work against perfectly silent opponents, such as incorporeal creatures.