A windshield is a great thing, but if the turbulence interacts with your helmet, you can get some ugly noise and buffeting. So, change the height of the shield or add an edge deflector to alter the location of the turbulence. The turbulence is there, you just need to move it to where your helmet isn't.
Is no windshield better? Maybe, if it's a really bad shield that provides no flow velocity reduction over the helmet. Basically, the sound level is going to increase by velocity to the 4th power, or higher, (dB ~ Log10 (Velocity)**4+ ). So, reduce the flow velocity over the helmet, then work on any issues arising from shed turbulence.
I use the pretty Howard Leight Laser Lites under a Shoei X11 or an HJC Symax. The modular helmet is noisier than the full-face due to the additional gaps which present a multitude of opportunities for disturbed flows.