my 2017 roadglide special at 20K miles no modification on the fairing. At about 40+ mph, I hear this annoying high pitch whistle coming from the front of the bike. It gets louder when I speed up.

I closed and opened all three vents, but the noise still there. My windshield is secure. Nothing is loose. No added accessories. I have changed my helmet but still there.

Where else should I look for?

 

Finding a noise over the internet is tough, and it could be reflecting back from the windshield. Since you have no modifications on it, this is a factory "installed" noise worth a trip to the dealer for them to sort out.

 

I don't remember where I saw a fix for this, but I remember it was definitely talked about when the 2015's came out. I would post on the road glide forums.org

 

Read about a whistle coming through the hole in the front axle and rotating it to eliminate it. Don't know if this applies to your machine or not . Just a thought.