On Jun 22, 2007, Dave commented:

I have been disappointed with the audio quality of some CDs I have
bought recently. Is there a free program I can use to get an accepted
measurement of fidelity? (like a signal to noise ratio)

I have my suspicious that some may have been stored an MP3s and then
"unripped" in the factory. So how can I tell for certain if my CD has
been an MP3, or other lossy format? I'd hope mp3 storage would leave
different markers than the original tape, for example.
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If they're major-label CDs, I'd be floored if they were making CDs from
data-compressed files like MP3s. There's just no reason to do it.

There have been cases where pirated recordings or shared files have been
"up-rezzed" from lossy files, and radio stations have sometimes used lossy
files on air (particularly commercials). I found this on the net:

For some odd reason, there are people who foolishly convert MP3 files to FLAC
(or APE), perhaps in the mistaken belief that it will make the signal "sound"
better. This is the sonic equivalent of taking a 1" square photograph and
blowing it up to 10", believing it will look as good as an original 10"
photograph.

"A shareware Windows program called "AudioChecker" can analyze various kinds
of FLAC, APE, and other lossless files and then intelligently make a guess as
to whether the files are legit or just "uprezed" from an MP3 file, based on
technical factors like frequency response. AudioChecker is available from:

http://www.dester.hu


I haven't used the program, so I can't say for a fact that it works, but MP3
artifacts are very noticeable if you know what to listen for. I don't doubt
you're hearing something bad, but it's possible you may be hearing some other
kinds of distortion in the track.

--MFW