Comparison of loudness calculation procedures according to ISO 532-1 and DIN 45631/A1

In 2017, the standard ISO 532-1:2017 "Method for calculating loudness - Part 1: Zwicker method" was published. The method described in this standard for calculating loudness of time-varying sounds is based on the algorithm published in DIN 45631/A1:2010 "Calculation of loudness level and loudness from the sound spectrum - Zwicker method - Amendment 1: Calculation of the loudness of time-variant sound". With the publication of the German translation of ISO 532-1:2017 (DIN ISO 532-1:2022) in 2022, there are currently two DIN standards available that describe the calculation of loudness using the Zwicker method for time-varying sounds. In this paper, the two methods, described in ISO 532-1:2017 and in DIN 45631/A1:2010, are compared and the extent to which the calculated loudness of the two methods differs is investigated. These results are used to check whether the results of ISO 532-1:2017 are within the tolerances for loudness calculation described in DIN 45631/A1:2010.