Can't speak from a pilots seat but the back of the S-92 is quieter than a Black Hawk, Chinook or even an AS332, most of the cockpit noise comes from the cooling fans,and yes the rotors and vibs, have any of the european operators had the CSN done to put the hushkits on the fans yet? and if so any noticable drop in noise?
Still not done yet here in Oz.
The main problem here is heat stress for the crew.....of S-76's and AS332's, Super Puma crews comeback after 4-5 hrs in 35oC + looking like been in a sauna, 92 crews happy with aircon, though the supposed high comfort seat could do with somemore padding!