some helmet gameplay ideas?

I was just think that would be so sweet!!! What are some of your guys ideas?
one helmet makes your radar better
another makes incoming grenades more apparent
another makes enemy footsteps louder

what are some of yall guises ideas ?

not a horrible idea, but I personally prefer when cosmetic stuff stays purely cosmetic. I want to wear the helmet I think looks coolest and not be forced to wear the helmet that enhances my ability to play.