It wasn't not being able to hear music that I was worried about, but actual hearing loss. The noise w the OEM shield was louder and higher pitch because it was concentrating the jet onto the helmet, instead of (without the shield) being dispersed all around the bike and onto the rider.
So with the shield, definitely would need ear plugs to mitigate wind noise/trauma and potential gradual irreversible hearing loss.
Without the shield, relatively quieter, but still at highway speeds, ear plugs make a huge difference. Any time I start a ride having forgotten to wear them I notice the difference immediately and actually stop on the side, put them on, and resume. That's why they don't leave my riding pants pockets.
Unfortunately it seems like any other good option would have to be a huge sail of a screen which will destroy the look of the bike and at that point might as well ride a cruiser, or a car.