As mentioned previously, any DOT/SNELL helmet should do the job--modern manufacturing levels the playing field quite a bit. Helmet price is almost a political subject, so get something that looks good and fits good. In many cases you'll be wearing it for hours and "hotspots" are incredibly distracting.
Wind turbulence causes progressive hearing damage, so get comfortable earplugs too. It becomes incredibly (jet engine) loud and causes fatigue. While stopped, I can converse normally with my FF helmet on and plugs in. I've NEVER had a problem noticing sirens, screeching tires, engines or other road noises. I don't have special hearing either; illness, surgery and age have weakened it noticeably over time.