Revision of stand alone standard, ECMA-418-1 for the detection of prominent discrete tones using tone-to-noise ratio method and prominence ratio method

In 2020 December, ECMA-418-1 1st edition was published as a stand alone and dedicated standard that specifies two parallel detection methods for prominent discrete tones in noise emitted by Information Technology and Telecommunication Equipment. The two parameters are, so called, tone-to-noise ratio (TNR) and prominence ratio (PR), which were developed in an informative annex of ECMA-74, in 1980's and 1990's respectively. The 1st edition of ECMA-418-1, December 2020 was derived from ECMA-74:2019, Annex D. The 2nd edition was subsequently developed as minor revision, in 2022 December. And, the 3rd edition is planned for the end of 2023. This paper reviews the history of the technical challenges in the standardization both of TNR and PR, and mentions the standardization (clarification) of terminology planned for the third edition and other issues. In addition, differences from the similar standard, ISO/PAS 20065 etc. that were compared and contrasted during this standardization processes are also mentioned.