Gees, I used my old DC (sans ANR) for years and flew noisy singles and Islanders etc with them. If the radios are any good, just cut an ear plug in half and voila, peace and quiet for the fraction of the cost of ANR. (That is, stick the half ear plug thingy in your ear + the trusty DCs)
Plus! Hearing protection when wandering around the ramp without your mega flash (read exy) head sets on.
Ah ha! You say, he might get run over cos he can't hear the evil fuel trucks or baggage carts bearing down on him. He'll have his trusty Hi Viz on so he'll be safe.
Lots of people are dismissive of DCs. However, if you're operating far away from a comfy city with lots of support, DCs are your head set. They work plus the back up *should* any thing go wrong is good. Also, they are field repairable.