I used a set of the Bose in-ear noise canceling for time in the back as the IRO, relief pilot. As good as the A20's. Really nice and cheap. Then I started using them in the cockpit over water. Same. Then I started using the Telex cockpit installed mic, with the Bose in-ear.
Over the next 3 years about 30% of the folks I flew with did the same. Then Bose came out with a 1200 dollar copy of my damn invention. I guess the horse already left the barn on that patent.

I like the new Bose in-ear aviation headset. Except I was doing the same thing for 4 years for 900 dollars less.