Any analog system (at least until when/if laser/optic players are perfected) will produce at least SOME noise when a recording is played...shellac more so because of the coarser "filler" included in the compound from which the records are made. In any case, as long as there is physical contact between the playing device (usually "stylus") and the sound source, there will be friction which in turn generates "noise." OTOH, photons bouncing off of CD surfaces apparently don't generate any (audible?) noise. One wonders, though, if these photons can, in theory, knock molecules from the plastic surfaces (in which case, CD's might show wear after a gazillion or so plays...?). The problem is, though, that as each reduction in the physical size of the "stored information" took place, the amount of damage needed to render the "record" unplayable also became closer to invisibility! (Side question...could a magnetic tape become useless if enough oxide was removed from the layer thereof?)