A lot of people use Bose and David Clark, I know of several people who use the Lightspeed Mach 1, I just purchased it myself. I have heard from several sources that the CRJ is a bit quieter than the ERJ. Don't know from my own experience though. I have the Bose (that I have been using for the past year or so as a CFI) but wanted something smaller and easier to haul around an airport.