Originally Posted by
Hot and Hi
While an ANR headset would also work in a turbine, in some turbine aircraft least the high-pitched engine or gearbox noise is so loud and concentrated on a constant frequency, that turbine pilots are often advised to further passively block they ear with earplugs (or well sealing helmets, or with in-ear communication systems, which practically are earplugs, first and foremost) to protect their hearing in the long run.
FWIW, that has been my experience in mil aircraft, but not civil. I took my civilian DC ONE X with me on a trip last year and I'm glad I did. The headsets they supplied us were horrific torture devices (we did not have helmets) and my head is already pointy enough
. I had a high to low impedance adapter widget and it worked great along with the DC ONE X, but the whine from the UH-60 gearbox was still very noticeable and quite fatiguing. Particularly since it is right over the crew compartment. Extra ear plugs helped. Overall it was still a better solution than that provided. But it doesn't seem to be a big problem in civil aircraft.
Lastly, the view that ANR makes it more difficult to notice the low RPM warning horn I consider an urban myth. Paul Cantrell and other authorities have commented on these pages on this question.
Never had a problem.
There is also the myth that ANR anti-noise somehow creates a higher SPL at the eardrum than passive. That's tough to explain to people who are not technically inclined and don't want to be.