Roadrunner, I had, what I think is the same issue. Next time it comes in, counter lean the bike left and right, and see which side is louder. If it is louder on one side, it's a wheel bearing/axle issue....
That is what my problem was. The first time it happened the guy checked the entire front end completely over, re-lubed and re-torque the front axle to spec, and it went away.... After about 2,000 miles it returned on cold, and especially humid days (gummybear). When it gets warm, it never happens.
So, along with doing the "lean test", also pay attention to how cold it is, and humid. Currently I've done about 8,000 miles since the re-adjustment from the shop, and it fades in and out, but no issues. I'm going to have it check out next big service, or maybe re-lube the axle if I get a chance...
Since I have the same concern as you about people staring at me because my bike makes a squeaking noise, I've just learned to brake much harder. It seems to fix it, but it is not the brakes, because with my bike, it would do it with the caliper removed, which eliminated the brakes. Give it a shot, see what happens.