I have the Complete Adventurer, and I saw these two feats:
Hear the Unseen
Benefit: 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.
Benefit: You can make one Spot check and one Listen check each round as a free action.
Normal: Using Spot or Listen in a reactive fashion is a free action, but actively trying to make a Spot check or Listen check requires a move action.
If I have both, do they combine and let me use Hear the Unseen as a free action? I'm assuming they don't, but I wanted to be sure, because of what it says under what normally happens without the Quick Reconnoiter feat.