You *seriously* need to change those ASAP. They are quite possibly the worst headphones around. They cut out 95% of what you *should* be hearing - the actual music! The quality on those is just plain awful. Get some in-ear noise cancelling headphones, and you will feel like you are on heaven. For real.I only have one set of headphones and they're my iPod headphones.
My UR-30 set would still be in use if the plastic 'skin' over the ear-surrounding foam had lived as long as the speakers themselves. A pity, because they are good, even (or especially) when driven by a solid-state amp. that I built in 1978, and which still performs flawlessly.I haz KOSS UR20s here ...