Saturday, September 25, 2010

Another Blast

At a recent meeting of broadcast engineers in our part of Ohio, the conversation at one point turned to the issue of wild audio levels on television. I've commented before on this site about the problem of audio spikes: those sudden surges of loudness that blast your TV usually when programming cuts to commercials. The problem has always existed to some degree, but has been made worse with the advent of digital television and its higher dynamic range. The broadcasting industry is feeling pressure not only from viewers but from congress, believe it or not, to bring these audio spikes under control. Believe me, we'd love to. But nobody seems to know how.

The obvious cure would be for TV stations to employ the same kind of balls to the wall audio processing many radio stations use. Your neighborhood radio station - especially the AM stations who have a hard enough time being heard - route the audio through a series of devices that act as an automatic volume control with the end result being you don't have to keep juking the volume knob up and down to hear the radio over the road. (Chances are your car sound system has its own auto volume control that adjusts based on your speed or, on more sophisticated systems, ambient cabin noise.) That is unless you're listening to NPR, who feels adding such artifacts to their product would be an insult to the audience, so trying to hear All Things Considered over the traffic noise requires listeners to serve as their own master control engineer.

The side effect of radio's power processing is that radio listeners rarely experience audio spikes. Problem solved.

And yet, in TV, we're still struggling to keep our viewers from getting a sonic lobotomy every time a local car dealer takes to the air.

Most TV engineers I know loathe to strap on the heavy-handed audio processing used in FM radio. Some networks want local affiliates to air their programming via an audio chain bypass. They claim that such processing adds to a feeling of bombardment for the audience - what we call audience fatigue. They have a point. Years ago, many TV stations did use the same audio chain as a radio station, and I recall the side effects could be awful. Prolonged silence on a movie caused the auto gain to crank up, bringing up the background noise. Then somebody would finally talk, and it sounded like a cannon shot.

This issue still crops up from time to time. The worst show on television - for more than one reason - is Poker After Dark. A bunch of guys sit at a table and stare at their cards... for ten frickin' minutes at a time. Nobody talks. The only audio content during this time is the poker chips, shrill plastic clacking, over, and over, and over, and over. And then they go to commercial. BLAST!

This reveals the root cause of much of television's difficulty in controlling volume spikes. In radio, programmers attempt to keep the medium engaged in constant activity. (Except for NPR, of course. Your tax deductible contribution pays for a lot of dead air.) Silence is not golden; it's death. Consistency is key. Keep the meters moving. In television, however, audio often serves to underscore the visual. It's considered perfectly acceptable for actors, particularly in dramas, to stare at each other just long enough for the master control room's silence alarm to beep.

Advertising agencies are also well aware of the inconsistencies of TV sound, and use it to their advantage. Consider this scenario: an episode of Law & Order goes to commercial. You get up to go to the kitchen for a snack. You're not watching, but your ear is still following the TV audio, but not really listening, just hearing the "buzz" of activity. Now, about a minute into the break, a clever spot comes on where the actors just stare into space. No sound. No sound. No sound. And then at about 15-20 seconds into the 30 second spot, the one actor yells. "YES! I WIN!" Our two actors were watching two snails as they creep towards a finish line. Snail racing. It's like waiting for your email on Brand X's broadband internet service. Clever. I should be a copywriter.

Think about how the viewer responds.

We've had a consistent buzz of audio activity over several minutes. Your ear has grown accustomed to it the same way you might grow accustomed to the hum of the fan in your computer... until there's a power failure. The silence is deafening.

The sudden silence gets the viewer's attention. Something's wrong. Did the TV station go off the air? Is there a problem? I gotta look.

And you look... just in time for the punchline and the commercial's message. GET CRAPCOR HI-SPEED INTERNET.

Meanwhile, for viewers just sitting there, and for master control who just woke up and reached for the switcher just in time for "I WIN!" to blast him to the edge of losing bladder control, this whole commercial has been nothing but an annoying exercise in lame comedy being used as a conveyance for another overexposed product or service I have no interest in. And this happens at least once a half-hour, for all of prime time and well into the late night lineup, every night, for usually two or three weeks.

And every time it airs, the station transmits another 30 decibel audio spike that could get us in trouble with the FCC.

Since it's highly unlikely that the FCC will tell content producers to watch the audio, or send a reprimand to the agency that produced that Mountain Dew spot where guys whisper for 15 seconds and then a woman emits a 30 decibel spiking eagle screech (oh yeah, that doesn't get old after four hours) broadcasters have little recourse but to use whatever means available to clamp down on the wild volume surges. Don't be surprised if your local TV stations start sounding like ROCK 96.3.

It's either that or master control operators start wearing Depends.


Frederick R. Vobbe said...

The problem with TV audio is two-fold. First, the mindset of theatrical audio has blessed the broadcasting business. These are two different animals in my opinion. Theater sound is designed for a large room, multispeaker system, and the dynamic audio structure that has you in the room with the actors. Broadcast, because people are generally listening at home tv's, some of which sport 4" speakers, needs to have less dynamics, and more control over soft and loud passages. The term "consistency" comes to mind.

Some of the producers of shows are also sticking their noses into this debate, causing much of the problems. Two networks are insisting that audio be passed from network to home without level control. Unfortunately, a program, with commercials and promos includes may have as many as fifty producers, all insisting their levels are the benchmark. How do you get consensus on 50 standards? Imagine in radio if the level of every song, commercial, liner, promo, jingle, and news broadcast was dictated by the person recording it? And that's the problem with TV audio.

I had an opportunity to speak with an audio tech who produces some of the shows we air, and he admits that there should be consistency, but each show audio producer has their own way of presenting the final product. After pinning him down on some specifications he admitted there could be as much as 9dB difference from show to show. (3db is half the loudness).

Finally, I'm finding NO manufacturer of 5.1 surround sound audio that employs the circuitry to keep levels consistent. Orban comes the closest, but till I can test it, the jury is out. The Orban unit advertises that it supports the CBS Loudness Curves, but it will be interesting to see how it controls level differences. What we need is a radio processing approach to TV audio. Let's hope that the viewers don't abandon us before the solution is found.

stevef said...

I should add that consumer end volume control solutions, notably from SRS, do a fine job of clamping the spikes, but with a trade off of adding a touch of POWER 102 compression to all audio content - and sucking the life out of the bass response. I have to remember to switch out the auto control when I watch a DVD - although some DVD's sound better with it on.

Ralph said...

I hope there's a standard solution built in to TV sets. The Magnavox "smart sound" patent is claimed to have been awarded in 1992, so it should be expired at this point.

Until then, I'll avoid the obnoxiously loud audio by skipping the commercial entirely.