My 2007 Ion front end sounds like I have snow tires on. I put air in my tires and had the tires rotated but it is still loud. What could be the problem?

Checking for uneven - scalloped tire tread: Rub hand from front to back - then - from back to front on tire tread - feel rougher one way than the other? Beyond this *hands-on* assistance will be required - recommend having ‘experienced’ mechanic test drive.