I guess that relates to how good the quality is and what you do with them. I have several closed ear and ear buds and both last me a long time (over 5 years). Some brands offer replacement ear pads (like Koss) and I have one pair of their phones that is at least 10 years old.
Wow, I need those tips gofar. I guess mine are always malfunctioning because of the way I handle them. Owning a pair of these for more than 3 years would be a milestone for me.