Broadcasters listening to loudness level set in Congress
Oct 12, 2009 8:00 AM, By Michael Grotticelli
NBC’s Jim Starzynski, who testified before the House Subcommittee on Communications, Technology and the Internet, said the proposed ATSC Recommended Practice eliminates possible ambiguity about the process for managing program loudness.
NBC Universal has been a long time proponent of the ATSC DTV Standard and took a leadership role in the S6-3 experts group. In January of this year, NBCU completed a dialnorm initiative for all of its cable properties. NBCU Local Media (owned and operated stations) completed its loudness and dialnorm initiative in December of 2007. The company is now in the process of testing file-based scaling technology that will automatically adjust commercial loudness to -24LKFS, NBC’s specific target value and the figure recommended in the ATSC RP document.
Across its cable properties NBCU uses specific program delivery requirements and the Linear Acoustic AeroMax system to manage loudness. The NBCU DTV network and stations do not use any external audio processing, mandating instead that program and commercial providers deliver their material at the NBCU specified loudness. NBCU’s goal is for all audio to be delivered to the home exactly as the content creator intended.
The National Cable & Telecommunications Association (NCTA) is also working with its member cable system operators on a loudness and dialnorm initiative.
On Thursday, Aug. 27 in conjunction with the NCTA, NBCU performed a series of network-to-cable operator tests to confirm loudness of its USA-HD channel across many points of cable distribution.
“The most important outcome of the ATSC S6-3 process (and perhaps even of the congressional intervention) is that much of the industry, including all the networks and PBS have joined together and formed a consensus on how to do DTV audio loudness‚” Starzynski said. “This is a huge accomplishment made possible by working in a expert’s environment within the ATSC and is a leap forward for DTV audio.”
“The disturbing thing about audio loudness is that there has been a mandated specification on the books since 1995, but not many have chosen to adhere to it,” Carroll said. “The problem is that it is a lot of work for broadcasters to get right, and not many have been willing to expend the necessary resources.”
Those resources include investing in loudness meters for audio mixers and/or automated audio processing technology that monitors signal levels and corrects those out of the recommended specification.
The International Telecommunication Union (ITU) has established a recommendation for audio loudness measurement that is recognized around the world. The proposed ATSC RP recommends those algorithms from the ITU specification. With the ATSC RP and ITU standard in place, the industry in the United States will finally have a universal DTV audio measurement recommendation.
“The ITU is also working on a loudness recommendation for content exchange when audio is delivered without metadata. Domestically, the ATSC’s proposed recommendation of -24LKFS will aid all broadcasters, operators and creators in the distribution and production of content when metadata isn’t present with the material.
“I really thought there would be a mad rush to get audio level consistent by the end of analog TV, but that didn’t happen,” Carroll said. “I am aware of cable operators that are stomping on the local stations’ signals in a profound way because they need to stop viewer complaints and have been left with no choice. That’s why we are stressing to broadcasters to get it right on their end and preserve the integrity of their programs. And now we’ll have a published [ATSC] recommendation that the broadcaster can take to the cable operator and collectively solve their problem.”
With the work in the ATSC and its RP at completion, there is a movement toward coordinated voluntary compliance in the industry.
“I’ve seen some real progress happening on this front, so I am optimistic that the industry is aware and working to give the audience the best possible DTV audio experience,” Starzynski said.
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