Originally Posted by
mville
Ah, OK. I think what you are asking is how can we be sure that the source material for an audio CD is not mp3 or similar.
Well, the simple answer is you can't. Maybe, Pink Floyd - Dark Side Of The Moon was mastered on cassette. We will never know, for sure. Often, the recording process is printed on the artwork, but that does not mean it is true.
It does not matter how the music is recorded/mixed/mastered, what matters is, does it sound any good.
... and audio CDs are not in wav format, just something very similar (equivalent) to wav.