If you heard a coworker saying mean things about you to another coworker, would you confront him or her?

Would you address this (in a calm, cool, collective manner) or would you leave it alone and hope it pes? If you wouldn't address this coworker privately, how would you handle it? I know that in a work environment, everyone has something said about them at some point, but do you mind if your coworkers talk about you constantly? Please...no rude or sarcastic answers. Please don't direct your answers towards me. I want to know how YOU would handle something like this. Thanks.