A paper for the technically minded.
The Numerically-Identical CD Mystery: A Study in Perception versus Measurement
"The authors have for some time been involved in an investigation into claims that numerically- identical CDs can sound noticeably different on replay. It has been suggested that these differences are attributable to variables in certain processes in the CD production chain. The work has centred on the controlled pressing of a set of test CDs encompassing the suspected variations. The discs contain test signals as well as music, so that listening test results can be compared with objective measurements from the same physical discs. This paper describes efforts so far in comparing listening test results with 'conventional' audio measurements. The work is on-going."
Link:
http://www.prismsound.com/m_r_downloads/cdinvest.pdf
The Numerically-Identical CD Mystery: A Study in Perception versus Measurement
"The authors have for some time been involved in an investigation into claims that numerically- identical CDs can sound noticeably different on replay. It has been suggested that these differences are attributable to variables in certain processes in the CD production chain. The work has centred on the controlled pressing of a set of test CDs encompassing the suspected variations. The discs contain test signals as well as music, so that listening test results can be compared with objective measurements from the same physical discs. This paper describes efforts so far in comparing listening test results with 'conventional' audio measurements. The work is on-going."
Link:
http://www.prismsound.com/m_r_downloads/cdinvest.pdf