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Hopes still Pegged on clear loudness guidelines

Simon Pegg, research and development director at UK manufacturer Eyeheight, talks to Kevin Hilton about the lack of firm guidance on loudness and how output limiting might still have a part to play in controlling sound levels.

Manufacturers and developers have their own views on what technology can do and what new products should offer the market but this individual technological creativity is being ever more shaped and prescribed by technical standards and recommendations from research institutes and regulating bodies. It’s a necessary fact of life, of course, but when companies go to the trouble of incorporating the latest rules into their products, they are understandably annoyed when the very people the regulations are designed to help and protect do not embrace them in the same way. Like many in the broadcast industry, Simon Pegg (pictured), research and development director at Eyeheight, has been absorbing the mass of information about loudness that has poured out from the ITU, the EBU PLOUD working group and other organisations in the last five or so years. So he was puzzled when the first of the new standards drawn up by the Digital Production Partnership (DPP), the collaboration between the BBC, ITV and Channel 4 designed to create common technical standards for delivering HD and SD television programmes in the UK, seemed vague about the supposedly burning issue of loudness. “Given that loudness is such a big thing right now this was a great opportunity to start doing things that are not covered in specifications before,” he comments. “People are using the current loudness standards in subtly different ways and there is nothing new in the DPP document so the industry doesn’t have an answer yet on how to best deal with the problem.” Despite the ITU BS.1770 and more recent EBU R128 algorithms and recommendations, Pegg says many broadcasters and post facilities are continuing to use PPMs peaking at 6 – which is allowed in regulations published by bodies like the Broadcast Committee on Advertising Practice (BCAP) in the UK. “It puts us exactly where we were before ITU and PLOUD,” he comments. “The DPP standard is a bit of a non-story on loudness as far as end users and manufacturers are concerned.” Pegg’s point is that there is a weight of research and standards on loudness already in existence, yet the implementation has been slow and apparently non-urgent. In the US the Commercial Advertisement Loudness Mitigation (CALM) Act, based on the ATSC (Advanced Television Systems Committee) A/85 recommendations, were approved by Congress in December 2010. This empowers the Federal Communications Commission (FCC) to draw up rules on audio levels between commercials and programmes, which will come into force this December. In another lackadaisical twist, the FCC won’t begin fining any transgressors until December 2012. There is now the potential complication of the ITU producing a second version of 1770, which formed the basis of the first wave of loudness specs and meters. It was also the starting point for PLOUD to begin development of what became R128. If 1770 II does appear, the likelihood is that it will implement most of R128 but with some different values. Pegg observes that loudness and ways of controlling it have turned out to “be more flexible than we expected”. His disappointment with the DPP document is that it doesn’t lay down proposals on the subject. “We thought there might be some numbers for guidance,” he says, “but they’ve not made any progress in helping viewers or broadcasters. Audio is the single biggest cause of complaints from viewers and having looked at the DPP specs there isn’t much to address that.” As chair of the DPP technical standards working group, Kevin Burrows, chief technical officer for broadcast and distribution at C4, looked at the various technological issues influencing digital TV delivery today. He acknowledges that there is a need to add more about loudness in subsequent documents but says now is still too early to make definite recommendations about this area. This is partly because the final parts of R128 were published only recently. The DPP will base any loudness specs on the EBU spec and will not be influenced by anything else, such as the possible part two of 1770. “We don’t want to change too much in the future,” Burrows says. In all the discussions about loudness the main focus has been on craft mixing using the new generation of monitors and meters that quantify comparative sound levels to produce a levelled, consistent output. But sometimes there is not enough time for a beautiful, golden ears mix hitting all the right parameters. Production of promos, packages and interstitials demands a fast turnaround, calling for a more automated approach. Eyeheight produces the KARMAudioAU plug-in for Final Cut Pro, which works with raw ITU 1770 and EBU R128 processed signals to hit target loudness and peak programme levels. An Avid plug-in is due to be released at NAB. Eyeheight also produces transmission output legalisers that will limit any discrepancies or deviations from specified loudness parameters. Simon Pegg describes the limiting as “very benign”. He adds that it would only kick in on very loud signals – such as gunshots – in material that had already been mixed through loudness meters. Pegg says the combination of craft mixing and automated levelling, with limiting as the final fall-back, should go some way to helping combat loudness, a problem that doesn’t seem to be going away any time soon.