What would cause a high pitched ringing coming from inside my chimney?

Question

It only appears in the cold weather months! It’s on and off all day and seems to be worse or higher pichted when it’s windy and or raining/snowing. I’m working from home now and it’s driving me nuts!

Update:

You can also hear it outside.

Answer 1

A piece of metal (flashing?) is just a tiny bit short. The metal expands in the summer heat and secures itself. In the winter cold the metal shrinks and then the elements move the metal around or otherwide manipulate the metal to create the ringing.  {Maybe I watch too many detective shows.}

Answer 2

a brick  broke lose and fell in forming a giant whisle . is your damper closed ? 

Answer 3

If there's some sort of cowel on top it might be causing it on a windy day.