We had our cabin air filter changed early in September. We usually have the fan on the second or third lowest speed setting. Last week we were on a trip to the mountains and had occasion to turn the fan up closer to the highest speed. When we did this there was an annoying vibrating/humming sound from the ventilation system - very constant, not the click-click-click sound of a leaf in the squirrel cage. Has anyone else experienced this after changing their cabin air filter?