If you do go ANR, at least get something that gives passive protection at the level of passive sets. ANR only works on low frequencies, and works on main rotor noise, only marginally on tail rotor noise, and not at all on turbine noise. Thus, if your passive protection isn't up to standard, you're getting greater hearing loss than you would with a good passive set. Check the NRR at all frequencies, not just the average NRR, in passive and active mode. If it falls off at higher frequencies, look elsewhere.