I thought my Sonata was quiet, but the Genesis is noticeably quieter. There are no rattles, wind noise and just a hint of engine noise. Some road noise but the roads in the UK are now third world standard. It was kind of eerie the first time my wife and myself drove around, and just talking normally (yes, I do talk to my wife)
It was noticeable that we didn't have to raise our voices. I think you tend to raise voice volume without realising it in a more inferior car.
Nick

Nick