Just a thought--I've always wondered if using a helmet chin curtain would cut down on the noise from turbulent air. I know that holding my hand where a chin curtain would go does in fact lower the noise considerably.
Might help in cooler weather. Would probably make fogging worse in warm or wet weather, unless you have a pinlock visor.
I installed a pinlock 70 on my stock visor last week, and wow!chin curtain absolutely helps cut down wind noise. i remove my chin curtain during the summer for better ventilation, but when it got cooler i put it back in to block the cool air. immediately noticed a difference in reduced wind noise. it does make the shield more prone to fogging, but the pinlock and breath guard insert helps a lot.