It could be the belt but it is very unlikely, the belts are very small and thin and if it were damaged badly enough to make a noise they usually break very fast. That said if your dryer is the popular 29" wide model raise the top while it is running and watch the drum revolve, if the drum kicks and or jerks with each revolution there may be a problem with the front drum bearing ring, rollers or even a bent or out of round drum. Also look and see if any of the screws that hold one of the plastic drum baffles in place are coming out sometimes they come unscrewed and hit the cabinet or top of the machine as it revolves, this also happens on the 27" wide dryers when the dryer top gets bent slightly as there is less than 1/2 " of clearance between the top of the machine and the revolving drum. Also on the 29"dryers sometimes a coin or something gets caught in the front bearing ring and it will make a funny sound as it turns.