Wuzzat?

http://www.windtech.com.au/wp-content/uploads/2012/08/13.pdf

Rent a strong fan to duplicate the problem. Run experiments. Make baffles or shields of varying sizes close to the window or nearby.

The pitch is related to the 'cavity' size and wind speed, like a whistle or a bottle with air moving across the top opening.

See what works and what doesn't.

CallMeVilla

Hate to sound obvious . . . Did you call the window manufacturer? They would hear about these kinds of problems and might have a fix. Why don't yuo post a picture of your windows with the solar shades? A close up of the trim and the corners might be useful too.

I bet it is the geometry of the trim. You can buy me a cup of coffee if I'm right.

Wuzzat?

And the shield can be something as simple as duct tape. If it works, the next task is to make something that works as well but looks better.

For auto problems of all kinds there are Technical Service Bulletins detailing fixes that work. There almost certainly is something similar that the window maker publishes that is distributed to installers.

With all the complaints about windows making noise when it's windy I could find no patents on window design that supposedly stops this problem.

Maybe the designs are good but the noise is primarily due to improper installation. Along those lines, when the people came to install our French Anderson doors they used the instructions as a hand towel. And yes, the installation was improper but the doors opened to a roofed porch so we were possibly spared problems because of this.