On the initiative of Eelco Grimm, five professionals from the audio field joined forces to write an ‘e-Brief’ for AES that proposes the introduction of a new loudness measurement called “PSR”, the Peak to Short-Term loudness ratio.
Companies from the authors (RTW, Nugen Audio, MeterPlugs) had implemented such meters and Eelco saw the need for harmonizing the algorithms to make sure users can fully rely on their experience reading such meters.
The abstract of the paper that was presented at the AES 143th convention in New York is as follows:
The “loudness war” still rages, but with major digital streaming services switching to loudness normalization by default, its end is near. Since absolute loudness is no longer effective at making music “stand out,” engineers are finding it much more effective to optimize microdynamics instead. The overall PLR (Peak to Loudness Ratio) of an audio track is widely recognized as a useful metric to assess the overall microdynamics of a section of audio and the likely results of normalization. However, short-term variations are also important, especially when judging the results of compression and limiting on audio quality, and these can be usefully assessed by a real-time property known as PSR (Peak to Short term loudness Ratio). PSR is found to be straightforward and intuitive to use, and several popular meters are already reporting it. This paper proposes a standardization of the term, to encourage consistency and adoption.
The e-Brief is available at the AES e-library: Measuring Micro-Dynamics—A First Step: Standardizing PSR, the Peak to Short-Term Loudness Ratio.