Toward a Recommendation for a European Standard of Peak and LKFS Loudness Levels

E.M. Grimm, R. Van Everdingen, M. J. L. C. Schopping

Complaints about loudness variations between program items are a well-known issue in television broadcasting worldwide. The cause is found in the replacement of skilled operators by automated broadcast systems. To facilitate automated leveling of program items, the International Telecommunications Union Recommendations Section (ITU-R) has published recommendation BS-1770, introducing the LKFS loudness measurement. The broadcaster's goal is uniform dynamics; thus a standardized loudness level needs to be accompanied by a standardized peak level. Most stations in Europe use the European Broadcasting Union (EBU's) PPM standard of −9 dBFS, and any new standard should be compatible with this. The analog PPM falls short in indicating fast (digital) peaks. These do, however, add to the perceived dynamic range, or rather the loudness-to-peak ratio (LPR). An additional digital peak standard is therefore needed before an LKFS level can be selected. Our research into the level practice of 50 international television stations suggests setting maximum digital sample peak levels to −5 dBFS and nominal loudness levels to −21 LKFS.

Print ISSN
Electronic ISSN
2160-2492
Published
2010-04
Content type
Original Research
DOI
10.5594/J11396