Squeaking/Rustling Front Windscreen

Has anyone heard a squeaky rustling sound around the outer edge of the front windscreen? The sound seems to come from the top edge of the windscreen, and around the side a-pillars?

At first I thought it was wind noise because I noticed it most at high speeds, but it has become gradually worse, and it is also very notable on bumpy roads at lower speeds.

Unfortunately, because it is so high pitched, it requires a passenger to get their ear up against the windscreen to approximately locate where the sound is coming from.

I suspect it is the front window seal that is squeaking, but if this is the case, I suspect others might also have heard the sound. Anyone...?