You can replace the ear pads, and you should. People typically don’t wear shoes for 4 years, and smell is just one of the reasons. Our ears and head and neck sweat, and it create odors and dirt, dead skin cells, and other debris that can be cleaned over and over - up to a point. I’m more frustrated that the headband wears out so quickly. If they had gone for a leather strap or some other different design, the headband could have lasted years. If you use these for 2 hours a night, for 100 days, they are done and need replacement, or the top of my head feels like...and the ear cushions still smell like a pair of old sneakers, 4 years later.