Apparently ANR creates "white noise" and this may disturb the hearing at different frequencies than non-anr headsets.
Best solution apparently is helmet with earplugs. secondbest is headset with earplugs, then headset/helmet with ANR.
Even the CEP system makes the user more prone to hearing loss, at different frequencise...
I guess it won't much matter what you do.
Apparently the worst culprit was the AS332L2. The article was written in Norway after several older Captains lost their medicals due to Tinnitus, a constant ringing in the ears.