Issue link: https://digital.copcomm.com/i/1546135
26 FA L L 2 0 2 6 I C A S Q U A R T E R L Y Here I am again, still ranting about the loudness specs we mix to for broadcast and streaming. This time though, it actually feels like progress has been made. The story so far—since the CALM Act took effect in 2012, we've all seen loudness spec sheets from the networks and cable channels specifying a LKFS target our mixes must conform to. This was based on a solid concept: Adverts are too loud—obnoxiously so, in many cases. ATSC, the Broadcast Standards Association, authored the document "A/85: Techniques for Establishing and Maintaining Audio Loudness for Digital Television," which laid out the best practices for achieving a more consistent listening level between shows and commercials and between channels. All loudness measurement is based on BS.1770, issued by the ITU, and there have always been a few ways to apply it in a practical sense. The most important distinction is what you are measuring. In the simplest terms, it's either going to be the full mix (termed "Full Program"), or one element of the mix, referred to as the "anchor element," which is almost always dialogue. Ad mixes tried to game the system with tricks such as inserting silence for a moment to skew the measurement down so the overall level could be boosted. And over the years, 1770 was updated to be more agile, account for these tricks, and be more accurate in its measurements. This is where problems started to arise. As 1770 evolved to better track the loudness of commercials, many distributors mistakenly thought that the way to measure loudness of the actual programs was also supposed to change, and this was never the intent. Dialogue is and has always been the anchor, and A/85 has never said otherwise. We've all been told that a mix with an average dialogue loudness of -24 LKFS (within the ±2 tolerance) is "not CALM- complaint" by someone who literally doesn't know what they're talking about. What this means in practical terms is that when you throw away anchored loudness measurements, the perceived volume of the dialogue in any mix is going to vary greatly depending on what sort of other content you have. And by "vary greatly," I mean get quieter. A dialogue-centric show with few big sound effects moments or a soaring score will have a similar dialogue and Full Program loudness measurement. But a big, epic, cinematic "premium episodic" show (or indeed a movie) may have its dialogue pushed down 6 dB, 8 dB, or even more depending on the creative choices the mixers and producers wish to make. This is categorically at odds with the intent of A/85, and categorically not CALM-compliant. That frustration is why we are here. The people who mistakenly thought mixes were all supposed to be Full Program weren't people who were, generally speaking, particularly creatively invested in the mixes, so they were simply by Jon Greasley CAS with Jamie Hardt CAS ATSC Loudness Spec Update: A DIALOGUE-GATED SQUEAKY WHEEL ADVANCED TELEVISION SYSTEMS COMMITTEE