Angus Kidman investigates the perennial question of volume and TV commercials.

Published in The Bulletin, August 6 2002

Ever noticed that the ads seem so much louder than the television programs they sponsor? You're not alone. The Australian Broadcasting Authority wants advertisers to turn down their spruik, but it's not as easy as just pressing a button.

Sound volume is usually measured in decibels, but perceptions of loudness depend on other factors. If a segment of sound has a wide dynamic range -- moving from quiet passages to more intense sections, and using a wide array of frequencies -- it will seem softer overall than a passage with limited dynamic range, even though both may have the same volume levels. Any recording can be "compressed" to limit its dynamic range and change perceptions of volume.

Compression is exploited frequently for effect in popular music, and few listeners complain. But when the same techniques are used to make TV advertisements stand out from the programs, viewers become incensed.

Such irate viewers now have governmental backing. After six months of serious TV watching, the ABA recommended recently that commercial television develop a code of practice to minimise those booming ads.

The Federation of Australian Commercial Television Stations says it will co-operate with the ABA in investigating such standards. However, it argues that the problem is ultimately impossible to solve, pointing out that any advertisement is going to be jarring following, say, Dr Mark Greene's funeral on ER.

Despite that stance, FACTS does recommend maximum levels of compression for use in advertisements. Advertisers are torn between not annoying viewers by being outrageously loud and making sure they stand out from rival ads.

A big part of the problem is that measuring overall "loudness" (as opposed to mere volume) is almost impossible using current equipment. Some broadcasters are pinning their hopes on the forthcoming broadcast loudness meter from audio pioneers Dolby.

But even if they can determine that an ad is far louder than anything surrounding it, are broadcasters ready to turn away advertiser dollars over a little noise?

Cynics would suggest "no", but the networks may not have much choice. If the ABA isn't happy with the forthcoming code of practice, it reserves the right to set its own standard, which stations would be obliged to comply with.