Not all circumstances are created equal. each environment is a unique situation and there is no one standard amount of time of when you should replace your ear cushions and wind screens. If you are in a call center operation using your equipment 8 hours a day everyday, you will certainly need to replace them more frequently than the occasional office worker. It is not uncommon to replace the ear cushions every 3 months. If makeup, seasonal illness, or degradation occurs, then you should replace them. They are more than just a "cushion" We have designed certain audio functional acoustic filters into the reticulated foam.
So the next time you look at your ear cushions and ask yourself "should I replace them" the answer is automatically, "yes!"