I get similar increased noise that seems to arise from transmission area. Told the dealership about it and , of course, they hear nothing extraordinary. Perhaps they are comparing the cabin noise with Elantra and Sonata by experience (no offence).
I have given up on service and customer satisfaction stuff with Hyundai. Just waiting for my lease to finish.
I had a 2010 Genesis, sold it, moved to Canada, and got a 2015 Genesis 3.8 HTRAC. You may have read my saga -- massive electrical failure while visiting California, and after 82 days, Hyundai gave me a brand new 2015 Genesis. This one had worked very well until 5600 km. Up until then, the car was whisper quiet. So quiet that 60mph feels like 40. Suddenly, I started hearing an undulating "note" coming from the frame. It sounds like tire noise being amplified by some kind of harmonic from the frame or suspension. Wah-wah-wuh-wuh-wuh-wuh-wah-wah (around middle C note). The sound literally drives me nuts, after experiencing such quiet in both my first 2015 and this new one (up until 5600km).
I took it to the dealer for the 6000km first service, and, predictably, the mechanic claimed he could hear nothing. Interestingly, the noise is somewhat quieter with a second person in the car.
I can detect absolutely no change in the performance or handling characteristics of the car. There is no noticeable vibration in the steering or suspension. Just the annoying wah-wah-wuh-wuh harmonic tune playing in the background.
My first Genesis made a strange noise at 1800 rpm, which I eventually decided was, again, some kind of failure to properly insulate or damp vibration. Again, several mechanics described it as "normal" when it decidedly wasn't normal.
I test drove several other 2010 Gennys, and although some made a related sound, it was barely audible, while mine was very noticeable.
Clearly, Hyundai dealers have no interest in helping out with these irksome NVH (noise-vibration-harshness) problems. I'm supposed to live with a car that now sounds like a low-end Altima. Hyundai is kidding itself. All the great advertising in the world won't help once the word gets out about these NVH issues.