when im driving down the road sometimes i here birds chirping in the front of the glovebox, its a faint chirp but it is enough to drive you batty on a long trip, i know of no other way to describe the noise, and im sure its coming from somewhere in the vicinity of the glovebox, maybe fresh air flowing through something with a bad bearing? i notice it when the heater fan is off, anyone else here the ringing in my head?

May be slightly loose dash/ glove box/ center cluster below dash/ etc. Try tighting all screws/ bolts/ nuts/ resetting plastic push pins, etc. A bit of a pain, but who knows.....maybe there is a bird trapped in there !!

Al