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Originally featured on BroadcastEngineering.com
Feb 22

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2/22/2012 1:31 PM  RssIcon

If there was any doubt about broadcasters’ interest in managing and controlling the audio levels of the commercials, short-form promos and long-form programs they distribute, a packed room of engineers gathered to discuss the issue this week in New York City was a telling sign. The group was made up of members from the New York chapters of the Society of Motion Picture and Television Engineers (SMPTE), the Institute of Electrical and Electronics Engineers (IEEE), the Audio Engineering Society (AES) and the Society of Broadcast Engineers (SBE).

It was the first time anyone could remember that the four groups had combined their meetings to discuss a singular topic; in this case one that is applicapable to all of the industries they represent. A government mandate that forces broadcasters and program distributors to comply with a new law (the Commercial Advertisement Loudness Mitigation, or CALM Act) or face the threat of fines apparently has a way of doing that.

The general concern is that while network broadcasters are now installing the required Loudness monitoring and signal processing technology to ensure compliance, many local stations are still not sure what to do. They understand the need to keep audio levels consistent, but don't want to spend money on technology that will not bring a clear return on investment.

Roughly 80 engineers assembled for a “milestone” meeting on Loudness.

“Consumers don't care about signal processing,” said Tim Carroll, president of Linear Acoustic (a company that makes audio loudness monitoring and correction technology), who gave a passionate presentation during the event. “And stations in many markets are risking that assumption that no one will complain. I think it’s a dangerous strategy.”

The new law applies to TV broadcasters, cable operators and other multichannel video programming distributors (MVPDs). It encourages broadcasters and MVPDs to work together to maintain compliance between them, as the last one to touch a program before it reaches the consumer is the one liable to be fined.

Several speakers at the event, which was held at NBC Universal headquarters at 30 Rockefeller Center, discussed different aspects of the new law, including enforcement, implementation and, above all else, the need to keep viewers happy. If a consumer sitting at home complains about the volume levels between commercials and programs, a station could be fined $10,000 for a single infraction.

Once a complaint is lodged, the suspect station has to provide the FCC with a 24-hour “spot check” of the outgoing broadcast stream (within seven days) to ensure compliance. If no one complains, stations will still need to provide spot checks on an annual basis for a period of two years. After that, stations that have proved they are not infringing on the law no longer have to spot check. Of course, the FCC has not specified how it will monitor stations’ activities on a market-by-market basis, or even if there is money to support it.

“Stations have to understand that the government is not fooling around and this legislation has teeth,” said Lon Neumann, Senior Technical consultant with THX, Ltd., adding that the commission will begin asking for spot checks in mid-December of this year. “We can't fight this, we have to figure out a way to comply, and soon.”

The specification that broadcasters must adhere to was developed by the Advanced Television Systems Committee (ATSC) over two years and published as the A/85 Recommended Practice in July 2010. The spec became law in December 2010. I October 2011 the ATSC released an expanded specification to cover alternative audio systems.

Jim Starzynski, director of Advanced Engineering & Principal Audio Engineer at NBC Universal, explained the care taken by all involved to develop a specification that includes all aspects of audio signal monitoring and delivery. He was one of the key people overseeing the ATSC committee that worked on the A/85 spec (which is at the core of the CALM Act) and finished their preliminary work in November 2009.

Speaking like a proud father, Starzynski said the A/85 document, available for free download, has been implemented fully at NBC Universal across both its television and cable properties. They utilize a house spec of -24 db for the Loudness level on all commercials being sent out with network shows. By automatically running every commercial (roughly 6500 per month) through an automated signal processing workflow, and in some cases using transcoding technology to make the spots comply, they are “certifying” that their channels are ready to meet the CALM Act requirements.

Tim Carroll, president of Linear Acoustic gave a passionate presentation about the need to keep consumers (viewers) happy in order to avoid Loudness fines.

In fact this “house spec” strategy is being employed by all of the networks (using different levels), as a way of maintaining their innocence should a local station be cited for an infraction. It also addresses advertisers’ concerns that their commercials are being “stomped on.” According to Starzynski, as long as every content provider is treated equally, producers don't have anything to complain about.

“We have to maintain a level playing field for all of our advertisers and program producers or this won't work,” Starzynski said. “At NBC we have certain requirements that have to be met. If you want your program to run on the NBC network and generally maintain its original creative intent, then give it to me the way I ask for it. It’s that simple.”

He said the way to determine the proper mixing levels when finishing a program or commercial is to identify an “anchor” sound within and then mix to that reference. The ATSC has said that the overall goal is to maintain most of the creative choices made by the program producer.

Next up, Ken Hunold, a Broadcast Applications Engineer with Dolby Labs, explained how to use Dolby’s Dynamic Range Control to create a mix that’s acceptable to both the government and the creative team. Interestingly, he also shared some listening research that found that at as long as the program audio level is from +2.5 to -5.5 of “Dialnorm,” viewers won't notice a different in loudness. At -10.2 to +5.5, they would get annoyed and change the channel or adjust the volume. [Dialnorm is the meta-data parameter that controls playback gain within the Dolby Labs' Dolby Digital (AC-3) audio compression system.]

Another issue discussed involved the challenge faced by MVPDs, which have to monitor not only single channel audio outputs but also the loudness levels between channels. As one might imagine, with hundreds of channels, this can be a daunting task if not done in an automated way. Jackson Wiegman, Product Manager with Evertz Microsystems, explained that the four largest MVPDs are responsible for 100 percent of their outgoing content while the next 11 largest MVPDs are only accountable for 50 percent of the channels they send out.

Linear Acoustic’s Carroll said the key to compliance for virtually everyone is the addition of metadata. If a producer embeds the loudness levels in the program stream, the broadcaster can simply incorporate that data into its playlist and feel secure that they are in CALM Act compliance. It will also enable a clip to recognize where it is being played on a small portable device or a large surround sound system and provide the appropriate data to make it sound good.

“Metadata is what’s going to save us,” Carroll said, “because it will allow broadcasters to keep their existing workflows while staying compliant with the new law. And consumers will have a much better experience moving from listening device to device. The alternative is more processing and creatively no one really wants that.”

For the roughly 80 people assembled for the “milestone” meeting, the general consensus was that, unlike HDTV, stations can't use “better signal processing” as a competitive slogan. But they can ensure that the station sounds good.

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