Opinions, Solutions Vary on Loudness Issues

By Dan Daley

Some people might have thought it was a little quiet on the show floor at points, but the issue of loudness was never very far away. The number of companies with a finger in that pie was substantial, from Dolby to Dorrough on this side of the Pond to Europe-based Junger Audio and DK Technologies. The range of asserted solutions is wide, from relatively inexpensive boxes from traditionally black-box makers like TC Electronic and Orban, to downright quaint battery-powered plug-ins for home televisions of the sort peddled on late-night infomercials.

But the most notable divergence of opinion, and one well-suited to NAB’s international ambience, seems to be along the Euro/North American axis, with European companies asserting not necessarily ultimate solutions but at least more experience and proactivity, with European trade organizations and governments weighing in on the problem of program- and commercial-level disparity with legislative mandates to get a technical solution in place and enforced. Last year, the UK’s Broadcast Committee of Advertising Practice (BCAP), the body responsible for writing the TV Advertising Code, published a new rule on sound levels. Since July, “advertisements must not be excessively noisy or strident. The maximum subjective loudness of advertisements must be consistent and in line with the maximum loudness of programs and junction material.”

U.S. legislation proposed last year by Rep. Anna Eshoo (D-CA) is equally vague, though less further along. Within one year of being passed, the Commercial Advertisement Loudness Mitigation (CALM) Act would compel the FCC to enact rules “requiring television advertisements not be excessively noisy” and would require the commission “to prescribe a standard to preclude commercials from being broadcast at louder volumes than the program material they accompany.”

That at least makes the use of a loudness meter like Dolby’s LM100 a good starting place. So does application of the International Telecommunication Union ITU-R BS1770 algorithmic solution (and ITU-R BS1771 requirements for loudness and true-peak indicating meters). Established practice for broadcasting analog audio is to peak the main programs at no more than +8 dBm, which means ads are restricted to +2 dBm, or PPM 4.5 on a peak-reading meter.

But it remains tricky because discrepancies in sound levels are subjective and advertisers are famous (notorious?) for wanting their ads to be louder then those of the competition.

Dolby sees the solution as needing to be implemented at the content-creation end. “At the content-creation end, our broadcast codecs — Dolby Digital, Dolby Digital Plus, and Dolby Pulse — all include metadata that can be used to normalize loudness across programs and channels and provide flexible control of metadata,” reads company literature.

Richard Kelly, a principal at measurement-systems developer DK Technologies, notes that Italy, Ireland, and the UK all very recently went with the ITA standard for control of loudness. But he says the U.S. lags on the issue not just legislatively but philosophically, by not making a sufficient distinction between loudness issues that appear over the course of a long program and those that happen between the program and the commercial. He says the former can be handled well with existing solutions; the latter, however, will require more work. He says DK’s metering can handle the sharper transients that commercials create but the market for them won’t become fully viable until the dual nature of the loudness equation is acknowledged. “I think that, later this year, you’ll see the matter being taken up in more depth in the U.S.,” he says. “It has to be; it’s a problem everywhere.”