Product plug: It's hardly novel to sing the praises of active noise-reduction headsets for airplane travel. I first learned about them in my piloting days, when the Lightspeed 20K headset made the difference between retaining at least some hearing and having to yell "Whaaat????" "Say that again..." for the rest of my life because of the literally deafening engine noise inside most small-airplane cockpits.

I didn't buy Bose aviation headsets because they cost twice as much as the Lightspeeds or other models, but the Bose "Quiet Comfort 2" model for airline passengers is a much better deal -- and not only because I got it as a Christmas present from one of my sons. I almost never see Chinese passengers wearing these on Shanghai Air or China Eastern flights (which, by the way, have much better meal service than most US lines -- topic for another day). But among American and European passengers on domestic or international flights they are of course more and more common:
Through the last month I was grateful for this headset during an interminable flight from Shanghai to Munich, and a few days later another from Munich to Denver. But somehow during one of those slogs, an earcup on the headset came loose from its mooring, so that the whole set no longer fit or worked.It didn't appear to be broken, but required an adjustment I couldn't see how to make without compounding the problem.