ATSC Releases Update of the CALM Act; Extends Coverage to Non-AC3 Audio Codecs

The Advanced Television Systems Committee (ATSC) has expanded the application of television loudness management techniques developed for and specified in the Commercial Advertisement Loudness Mitigation (CALM) Act to cover alternative audio systems.

Known as Annex K of A/85 and entitled “Requirements for Establishing and Maintaining Audio Loudness of Commercial Advertising in Digital Television When Using Non-AC-3 Audio Codecs,” it complements the A/85 RP’s Annex J, released earlier this year, which specifies AC-3 commercial audio loudness requirements.

Annex J covers broadcasters and others that use the AC-3 (Dolby Digital) audio system in the ATSC Digital TV Standard. Annex K applies to non-AC-3 audio systems used by multichannel video programming distributors (MPVDs), such as DirecTV.

Roger Charlesworth, executive director of the DTV Audio Group, says the new Annex will allow a more comprehensive application of broadcast audio loudness management techniques.

“When a network sends programming to another distributor that does not use AC-3 [encoding], now there’s a way to compel compliance with the CALM Act all the way through the distribution chain and beyond on-air broadcasting,” he told SVG.

Charlesworth adds that loudness monitoring and management would be the first of several online distance education modules that the DTV Audio Group has developed in conjunction with Turner Sports, Fox Sports and NBC Sports, which will be hosted by Learning Sciences. The module, now in a beta version available to audio operators affiliated with those three broadcast networks, will go live this fall.

“The addition of Annex K is the result of industry commitment and collaboration that has been the hallmark of the development of A/85,” ATSC President Mark Richer said in a statement. “We have established the parameters necessary for all service providers to meet the goals of the CALM Act.”

The CALM Act was enacted into law on Dec. 15, 2010 in response to consumer complaints about loud commercials and disparate audio levels between commercials and program content. It requires the FCC to adopt the relevant portions of ATSC A/85 by Dec. 15 of this year.

ATSC Recommended Practice A/85:2011, July 25, 2011, is the successor document to Recommended Practice A/85:2011, May 25, 2011. A/85 is available on the ATSC website,

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