Does this sound right?

Took the xmr out on saturday, 16 hrs on the clock. While riding down the trail it gets real bumpy. I was doing prob 6mph in low n every bump i hit i can hear the belt. Its not a sliping sound but it would make a short whine. As if it was coming under load for a sec then off. I was steady with the throttle. I didnt knotice any issues and inspected the belt after ward n it looks new. My guess was its the belting making noise coming under load and off as the bike was bouncing around but i just want to make sure.