Sorry, looks like I'm a little bit late to this party... At any rate, I have a 2012 non-R-Spec 5.0, and I finally found how to silence this tune. It's called "welcome sound" and I was able to turn it off by holding the DISP button on the steering
wheel for a few seconds. This activates the menu, which appears in the center of the instrument cluster (where the "cartoon" Genny shows up when the tune plays). From there, you can toggle it on/off and use the TRIP button to save the setting.
I found this Hyundai "commercial" cheesy and annoying. I couldn't find a way to get rid of the graphics; only the tune. But, getting rid of the sound was enough for me.
Cheers!