Very interested in after market ANR for DCs, please tell more anyone who knows. What sort of kit is involved? Any compatibility probs with particular types of radio/intercom, all that sort of thing. I have DCs but have recently concluded that, as my hearing is getting worse and my current a/c types seem to have noisier than average cockpits, I need to invest in ANR. If I could do that without having to bin my current headsets, which are only 2 yrs old, that would be a bonus.