No doubt, that is a horrible sound! OK, 1st guess is the belt has split a part of its self loose, and it could be flapping around, slapping the inside walls of the dryer is it goes around. Solution would be to replace the belt of course. Also, should replace the belt tensioner at same time. On this model, the tensioner is bad about coming apart, and it might actually be what damaged the belt. Have to take it apart to know for sure, so you can see the belt and the tensioner wheel. If they are not the problem, then check the drum support wheels, see if one is frozen in place, or has a flat spot worn onto the wheel that would make the noise as it is spinning and making contact with the drum. Again, you would have to take machine apart to inspect them, including removing the drum to see the support wheels.
Ken's Appliance Repair