Yep. Bearings will pop & grind and amplify right through the wheel. Sometimes a grain or two of sand will work into the bearing race and make noise... This won't happen until AFTER you clean the bike. It's a law of nature.
Once I adjust and tighten the bearing locknuts, I dab some heavy automotive grease around the area... It does a pretty good job of keeping grit and moisture out of the bearings.