I am hearing a sound as though a fan is rubbing on something while spinning. It is only intermittent. It sounds as though it is coming from the drivers side dash board location
Something may have fallen into your defrost vents and is now rubbing the blower fan. If you are lucky, a tech may be able to remove it without disassembling the dash.
Thanks!
Arnold
May your primary focus be on God and let everything else be incidental!