A chief engineer at one of the Big Three says dialog normalization doesn’t work while his counterpart at another says it does, but the disparity is complicated. Reining in the ear-bleeding peaks of television audio takes more than hardware and calibration, and what works for one infrastructure may not work for another.
“Dialnorm is ineffective 54 percent of the time,” said Bob Seidel at a conference this week in Rancho Mirage, Calif. Seidel is vice president of engineering and advanced technology at CBS. The network has made no secret of its dissent on dialnorm, parameters for which are required by the FCC.
Seidel was part of a panel of network engineers who participated in an audio summit at the annual Hollywood Post Alliance Technology Retreat held this week near Palm Springs.
The problem with dialnorm is temporal, he said. CBS measured dialnorm over 60-minute periods, but the outcome didn’t represent the moments going into a commercial break. The dialog within that short interval may range from quietly dramatic whispers to a caterwauling car hawker.
CBS did a few prime time audio measurements and determined a viewer comfort zone at around –24 dB, give or take a decibel or two. The network then proceeded to measure the audio levels of 809 commercials and found an average of –18 dB, i.e., the ads were mixed loud, or “hot.”
Advertisers have little incentive to tone down the audio because there’s no quantitative evidence that people run screaming from the room when the television suddenly bellows at them. Conversely, Hollywood producers use the widest possible dynamic range for dramatic effect, often mixing in ideal audio facilities that have no resemblance whatsoever to the acoustics of a household.
Broadcasters have implored both parties to put a little less English on their sound boards, but to no avail. The only other way to control dynamic range at the network and station level is to hire someone to ride it 24/7, a possibility most assign to the fat chance file.
CBS has addressed the volume variation with a loudness control play-out application that brings content into the comfort zone. The application was launched Dec. 28.
NBC meanwhile is working on ways to implement dialnorm throughout its distribution system, and considering some form of scaling to do it, said Jim Starzynski, principal engineer and audio architect at the network. The network’s use of Dolby E facilitates its implementation of dialnorm, according to a source familiar with the network infrastructures.
CBS uses Dolby E as well, but in a way that doesn’t necessarily help with the implementation of dialnorm. ABC, which uses Dolby Digital, is said to have “reservations” about dialnorm, but none were mentioned by the network’s senior vice president of telecom and network origination, Richard Wolf, who was on the panel with Seidel and Starzynski.
The March issue of Television Broadcast will provide more coverage of dialnorm and other audio issues discussed at the HPA Retreat.
Future US's leading brands bring the most important, up-to-date information right to your inbox
Thank you for signing up to TV Tech. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.