As stated on the first page of posts there is a major design fault and I would suggest not to buy until they fix it.
That is the ship powered version has to be manually switched on every flight.
After a while people forget to do this so they fly around with no active noise reduction.
How such a famous firm could make such a serious error is mind boggling.
Imagine if you are flying Bill Gates or the Queen around. You have to tell them each time how to turn on the headset.
Did a demo in the latest Bell twin and the pilot forgot to tell everyone how to turn on the headsets. Everyone commented on landing how noisy it was. Only then did the pilot admit that he forgot to tell all the passengers that they had to turn on the headset themselves.