My dad and i both have 2012 Ecoboost trucks... Mine is an FX4 and his is an XLT. His truck has a lot more turbo noise than mine. I can barley hear my turbos. Very faintly, but when im in his truck and he gets on it, you can hear them plain as day. You can hear the turbo spoola s well as the rush of air.

I think the FX4 has more sound deading materials in it than the XLT's. Maybe thats why there is a sound difference.