I'm curious why a CD would not work anymore after listening to it a lot? Is the laser powerful enough to damage it or is it the heat from the device itself which is degrading the material in the long term?
The polycarbonate substrate could degrade due to temperature, humidity, exposure to sunlight, and other environmental variables. These are concerns for institutions with large CD-based archives (e.g., Library of Congress). [1]
In practice, though, it's far more likely that the the disc will get corrupted from small scratches.
I have taken several CDs (mainly my Dad's, not my own) from unusably scratched to relatively pristine. The really bad cases need fine grit sandpaper (wet!) followed by plastic polishes. I generally start with Meguiar's plastic polish and work my way to Radtech Ice Creme. In my own collection I have CDs that are around 30 years old and are error-free. I'm not interested in formats or services that won't last at least as long or can't be backed up to my own NAS (nor am I interested in anything less than Red Book quality).
> I'm curious why a CD would not work anymore after listening to it a lot? Is the laser powerful enough to damage it or is it the heat from the device itself which is degrading the material in the long term?
If you handled everything with white gloves and carefully moved the CD around it would probably last forever under a realistic scenario (you left it in a closet, didn't move it around much, etc.).
I have a bunch of original CDs from my first music collection that still work after ~20 years based on spot checking some of them 5+ years ago. Even with hundreds of playbacks.
But, I do have a handful of CDs that I remember having issues. They skip in certain spots due to artifacts on the CD. The real world happens. I don't remember what happened exactly in each case, but I'm guessing they got scratched. Like maybe I didn't put it fully into the black binder that held 200 CDs and I hit a bump in my car which caused the binder to jump around and an edge of the CD got clipped by the zipper, who knows.
Also burnt CDs seem to have a much worse shelf life. They are much more susceptible to being damaged. I don't know exactly why at a technical level but for sure I've had more burnt CDs fail over time. That becomes an issue when you want to back things up.
With mp3s, I can just put thousands of songs on my computer and everything works all the time. I never had an mp3 not play or skip unless the file itself was corrupt initially. They are also a heck of a lot more portable. You can put your collection on your phone, throw in some earbuds and now you can go on a run, or a 6 hour plane trip. You ever try running with a discman[0]? I have. It doesn't really work too well haha.
I remember later discmans had internal audio buffers so the music wouldn't stop if you shook them, but I guess on a run the buffer would end up going dry and music would stop anyway.
In practice, though, it's far more likely that the the disc will get corrupted from small scratches.
[1] https://www.npr.org/sections/alltechconsidered/2014/08/18/34...