IEC 61606-4:2005 specifies the basic measurement methods of a linear PCM signal for an audio part of personal computers (PCs) and applies to both desktop and portable computers. The common measuring conditions and methods are described in IEC 61606-1. Specific conditions and methods of measurement for PCs are given in this standard. This bilingual version (2012-05) corresponds to the monolingual English version, published in 2005-12.