I'm not being facetious, but maybe just get used to it? I have a lot of reps and some of the rotors in them are silent, some are so noisy I can hear the rotor whirling at arm's length. I'm used to it and consider it part of their character. It's not something that's exclusive to rep watches - it's just a "feature" of an automatic watch with a rotating rotor.
But anyway, if you shared more details about which factory, model and movement you're referring to, maybe you'll get some more specific advice about your watch.