Why is do I hear a crumple noise followed by tapping when I turn on the air? on 2009 Hyundai Tucson

The air is not blowing like it should out but you can feel it just kind of leaking out. It has done this a couple of times but I left it off and tried it later with no problems. Now it does it more.

Asked by for the 2009 Hyundai Tucson
Trash in hvac (heater/ac) box, mode selector door problem.
is this easy to fix or costly?
Check with dealer,how many miles on your car?
ALMOST 51,000. I tried it again and noticed the air seems to be blowing out of the floor vents and still makes that tapping noise but a little air is blowing out the top vents like it's on low on all settings.