The 757's in MAN this week have been G-LSAD and G-LSAE. G-LSAC was the a/c that had the change. Believe that that one is in NCL now. Can't say I have noticed any difference in sound from either of the 2 a/c in MAN this week. However, when I fly on AD, I am convinced it sounds a little louder than the others, could just be my imagination though.