Heater Duct Fluttering Sound

My 2009 has had a fluttering sound from the heater duct for a long time now and it's driving me crazy! I don't ever remember dropping anything down there as I NEVER put stuff on my dash. Anyone else's tacoma make this sound? Also, is there a reasonable way to remove something from the heater duct without tearing the dash off?

 

bump ... sound is driving me nuts so I'm going to have to try and find it somehow. I just know if I take it to the dealer it will cost large $$$$

 

Is there some debris flapping around in the motor housing behind the glove box? I heard a flapping sound once (couldn't quite tell where it was coming from) and there was a maple twirly that had found it's way in there. Used a shop vac with flex tip to suck it out.