The rubber brushes on my Roomba S series failed in the 1st month when a nickel sizedfelt pad got sucked up and lodged in a location where it was in contact with the rubber brush. I have excellent hearing but did not notice the shafing. The Roomba gave no warning that an object was lodged and damaging the rubber brushes. A few minutes later, the flimsy rubber brushes had holes in them. So, you must watch for small objects such as paper clips. Even soft flexible objects will damage or break the rubber brushes.