Thomas Lund, CTO for Broadcast & Production with our friends TC Electronic, has been one of the driving research forces and leading experts in the field of audio loudness for more than a decade. At NAB 2014, on Wednesday April 9th between 3:30 pm - 4:00 pm he presents a paper entitled Loudness vs Speech Normalisation in Broadcast
Loudness vs Speech Normalization in Broadcast
The paper presents an empirical study of the differences between level-normalization of programs using the two dominant methods:
- loudness normalization
- speech or”dialog” normalization
Instead of adding to the continuing debate of the subjective merits of one method over the other, Thomas will be focusing on important technical aspects. and shows that the difference in normalization level between the two measures was up to 14dB.
For all films and programs the loudness method provided the greatest headroom. All programs and a majority of the films could be broadcast at a fixed Target level of -24 LKFS without dynamics processing.
Not a single film could be broadcast under the same conditions without applying dynamics processing. The study furthermore finds a notable and systematic difference between manual speech measurement and automatic speech measurement, in some cases more than 8dB. Uncertainties in classification, in measurement and in definition are described and compared against the requirements for precision in ITU and ATSC loudness-based standards.
An Alternative View Of Loudness Normalisation
This picks up on the issues that Jake Knott raised in his Alternative View of Loudness Normalisation. Anyone who is going to NAB that works in broadcast or audio post should try and get to this session. What Thomas doesn’t know about loudness isn’t worth knowing.