As the launch customer for the Grob 115 series in Canada {My wife and I owned a few flight schools, since sold to staff and customers, old age the only reason} I just cant belive that the RAF finds them to be too loud in the cockpit, we regulary flew eight hour aerobatic days, all are still passing our six monthly hearing tests, in fact the quack tells me Im in the top 5% of tested pilots, however if one looks at the hearing results for kids trying to join the CAF the results are bloody scary, the end result of boom boxes, loud rock and spending most of the day with plugs blasting into their ears,It all sounds a bit contrived, just like the "no pax flying" in DC3s!