ATSC Makes Progress On Loudness Problem

Approves recommended practice for broadcasters to follow
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The Advanced Television Systems Committee (ATSC), the U.S. digital TV standards body, has formally approved technical guidelines that networks and stations can follow to avoid wide variations in volume between different programs and excessive loudness in commercials.

The ATSC announced Wed., Nov. 4, its membership approved the “ATSC Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television,” which describes production, distribution, and transmission practices for providing high-quality audio soundtracks to DTV viewers.

The ballot was approved the same day the ATSC hosted a seminar in Washington, D.C. on the topic of audio loudness that drew top engineers from broadcast networks, cable operators and audio equipment vendors. The event was sponsored by the IEEE Broadcast Technology Society, DaySequerra, Dolby, Junger Audio, Linear Acoustic, National Association of Broadcasters (NAB), National Cable & Telecommunications Association (NCTA), RTW, and law firm Wiley Rein, which hosted it.

The problem of audio loudness has annoyed DTV viewers for years and has recently drawn the attention of Congress, with Rep. Anna Eshoo (D-Calif.) backing a bill, the Commercial Advertisement Loudness Mitigation (CALM) Act, that would require the broadcast and cable industries to regularize the volume of advertisements and the programming surrounding them. The bill has been approved by the House Communications Subcommittee and is seeking support in the Senate.

Much of the CALM Act would simply reinforce steps that broadcasters are already voluntarily undertaking to solve the loudness problem and which have now been formalized by the new ATSC recommended practice. The document focuses on audio measurement, production and postproduction monitoring techniques, and methods to effectively control loudness for content delivery or exchange.

It recommends methods to effectively control program-to-interstitial loudness, discusses metadata systems and their use, and describes modern dynamic range control. It also includes specific information on loudness management at the boundaries of programs and interstitial content.

“What’s important is that everyone is starting to move to uniform practices,” said ATSC president Mark Richer. “We have momentum already.”

Richer credited NBC Universal engineer Jim Starzynski, chairman of the ATSC’s subgroup on digital television loudness, with getting the major broadcast networks to agree to move in the same direction on how they measure loudness and set consistent values for “dialnorm” (short for “dialog normalization”), a metadata parameter that helps control how digital audio is decoded. He also said that the ATSC seminar on loudness drew strong participation from the cable industry, whose cooperation is vital to ensure a consistent listening experience for the majority of TV viewers.

ATSC members, including both network engineers and technology vendors, have heard complaints about the commercial loudness problem for years from family and friends. Richer said he is pleased to report that the industry has made significant progress on the issue.

“A lot of people have heard from their spouses, can’t you do something about that?” said Richer. “We said, we’re working on it. Now we can go home and say we’ve done something about it. The bottom line is, you shouldn’t have to constantly pick up the remote control to adjust the volume, it should just be to change channels. That’s where we want to be.”

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