But you agree that a cloudy area as most can cause static, muting or skips? It will not results in any audio shifts in frequency or levels, just noisy stuff like you describe.

A good sized cloudy area on the surface of a cd is not a couple of misread bits. 

It's technically impossible to get the type of modified analog output that is being described here. It's simply not possible to have frequency shifts and level shifts because of a couple of misread bits. NOT POSSIBLE. Exactly!! Static. Muting. Skips. All can be the result of a dirty or scratched disc! Not "improved soundstage" or any type of frequency or level shift. Here, we agree.

I'm sorry but I disagree.  I've had noticeable static, muting, skips etc from dirt which were fixed by cleaning.

There are 4 levels of error correction at play and even if they all fail, the first nasty correction is interpolation and the next step is muting. Neither of these levels will happen for a "dirty" disc, It would take a major scratch to cause these to kick in. The second level correction (muting) is sometimes audible (likely showing up as skips or pops) but not frequency or level shifts. If the errors are so severe that muting can't be done, the disc skips. This is not true. If the file is so corrupted that it can't be converted to an image, you'll get a partial image, not a changed image. Did you never have a corrupted download of a photo? It's usually looks perfect and then simply chops off where the data is corrupted. In the early days of the Internet, this happened often.