My company supplied them to our flightdecks a couple of years ago. Used them a couple of times but found that getting a decent volume balance between intercom and R/T was tricky. It was easier to use 'normal' headsets with 'one ear off'. No problem now though, if you want to use them you have to provide your own batteries! The tightwads in the finance department believe that they have avoided any legal actions resulting from high tone deafness by the supply of ANR headsets and it's up to the users to provide their own batteries!