Why are television commercials so loud?
by Gordon Campbell
Routinely, television commercials seem a lot louder than the TV programmes that precede them. Yet the urge to lunge for the remote and turn down the commercials (or mute them entirely) is not always driven by raw volume alone. More often, it is due to a compression process that pushes the sounds on the advert into the same blaring, attention -seeking range. And even more to the point, the ear is usually attuned during the programme to the sound level of the dialogue – which means that the sudden switch to a commercial sting can sound louder than any change in the actual volume.
Arguably then, the problem is really one of perceived sound – and because of this subjective dimension, the solutions that are now being tried do not simply stipulate an objective decibel level, and then pay close attention to a needle on a meter. There’s been a large degree of self interest involved as well. Around the world, broadcasters have been trying to respond to the constant stream of public complaints about loud TV commercials – but without using instruments that blunt the impact of the advertisements on which the broadcaster depends.
In New Zealand, says TVNZ’s general manager of technology Peter Ennis, all broadcasters are currently talking with each other to try and arrive at a workable loudness standard for television commercials. Regardless of the outcome of those talks, TVNZ will by year’s end introduce some new technology aimed at smoothing out the transition from programmes to ad breaks. Basically, it involves what Ennis calls an Axon Loudness and Measurement Processing Unit.
The core element involves taking a sample of the variation between loud and soft sounds – also known as the dynamic range – in the programme that precedes the ad break, and running this through a set of algorithms that will then set the acceptable levels for the subsequent ad break and/or trailer that follows. When necessary, it will adjust the sound level of the commercial accordingly.
Surprisingly enough, as the BBC says, the hard of hearing are often the viewers most annoyed by noisy television advertising. Again, the problem is one of perceived sound, rather than one due necessarily to changes in volume.
People who are hard of hearing tend to lose the ability to detect high-pitched sounds, with the result that low-pitched sounds can swamp the sound of speech. So when a loud advert (or a programme trailer – a source of many complaints among the hard of hearing to the BBC – comes on unexpectedly, the low-pitched sounds in the commercial, usually the music, are amplified and distorted.
Not that it would do anyone here much good to protest to the Broadcasting Standards Authority – which, when contacted for this article, told me in no uncertain terms that their concerns lie only with complaints about programme content. Routinely, the BSA tells aggrieved viewers to complain directly to the broadcasters. That’s not how things are done in Britain. Ofcom, the BSA’s British equivalent, has a far wider mandate. Recently, it ruled against ITV for playing some ads excessively loud, and fined them accordingly in a decision that has been widely taken as laying down a marker for the entire industry.
New Zealand is still playing catch-up. “There is no regulation around it,” Ennis says. ‘We have technical standards, which speak to peak levels rather than average levels.” From the outset, he explains, the international and industry standards were more about identifying the maximum sound levels at which damage might occur to the transmitters, rather than anything to do with the sensitivities of viewers.
Regardless, excess or irritating sound is becoming an issue for viewers and (belatedly) for smart advertisers. For a long time, broadcasters have had the ability to transmit audio of high quality – but until 10 years ago, few TV sets were able to play back audio particularly well. Now, more and more viewers are watching TV with stereo loudspeakers or on home entertainment systems capable of reproducing a greater dynamic range. The relative loudness of commercials, and the dynamic range of programme content are both becoming far more obvious.
Advertisers have pushed the boundaries of tolerance for years, and broadcasters have tended to go along with them, for obvious reasons. Ennis : “Advertisers, not unreasonably, because they’re paying a lot of money want to get their message out there and ideally, want their message to stand out in a crowd, So, quite often commercials will have a reduced dynamic range,, so the subjective experience is of a sudden jump in audio levels.” In a high intensity ad for instance, the dynamic range between the loud and quiet elements may be only 4 decibels, with everything pitched at the same ‘Buy! Buy! Buy!’ level. Yet in the preceding programme, the dynamic range can vary by as much as 50 decibels.
When commercial desire meets viewer resistance on a battleground like this, who is likely to win? Currently, the broadcasters are trying to stake out some middle ground. However, can anyone really set an objective standard for what may be largely a subjective experience ? Especially when the subjective experience of excessive loudness is based on a comparison – but most of the measurement tools available are capable only of measuring loudness at a specific moment ? Well, Ennis replies, the International Telecommunications Union (ITU) has been working on this issue with broadcasters and equipment manufacturers for a number of years – and the result has been a loudness recommendation called ITU 1770 unveiled in 2006-07, and available in full here.
The essence of ITU 1770 is a set of algorithms that tackle the problem temporally, and spatially. “ It doesn’t take an instantaneous sample,” Ennis says. “It looks across time and averages the audio around that instant, and also looks at the frequency component, and it does provide a measurement of dynamic range. The sampling involved is of the order of a couple of seconds…” Or, in some cases, micro-seconds. In other words, the ITU standard measures loudness, but does it at other than just peak levels. That is its alleged breakthrough. Beforehand, Ennis says, broadcasters could measure peak levels and average levels of sound, but couldn’t incorporate them into the one figure.
“The results are quite startling,” Ennis believes. “When we roll out that technology later this year, viewers will start seeing a difference. What it won’t do is heavily compress the programming. That’s been a difficulty with previous techniques. They’ve taken away from the quality of the audio of the programming…” Ultimately, as broadcasters move more and more to file-based programmes, the dynamic range of the entire programme will be able to be sampled and pre-tagged, thus enabling an even more subtle integration with the commercial break.
Advertisers may be happy about it – or not. What difference will it mean for production companies making television commercials ? Not much, Ennis indicates. He hopes the change may even be embraced by the advertising industry as an improvement on prior attempts at loudness processing. “We have an ongoing dialogue with production companies regarding audio levels, and sometimes that can produce a little bit of tension. I think they will broadly welcome the fact that what we will be using will be something a wee bit more sophisticated than the techniques used heretofore, which have been sledgehammer-like…” [In future] their commercials will pass through the transmission chain largely unaltered, apart from the loudness tweaks. Will they retain the same impact as previously? “They will. Their commercials will be played pretty much as they produce them. What we’re trying to do is reduce the jarring between the end of the programmes, and the ads. “
The Axon unit is being deployed alongside wider improvements to the audio world of television involved with HD, and 5.1 and 6.1 SenseSurround sound. Ideally, the Axon gear will sit in the background doing nothing most of the time – but it will step in to smooth out differential loudness levels and within frequencies as well, given that some frequencies (especially around the mid-range) often seem louder than others. Still, the new gear won’t do miracles. Some conflict between a contemplative drama and a shrieking ad is inevitable, and this won’t disappear entirely.
To date, audio has tended to be an also-ran in broadcasting. Ironically, while television deals mainly in pictures, viewers tend to be more critical of what they hear, compared to what they see. “ Its quite funny really,” Ennis concludes, “because there‘s a lot you can do with pictures before people will start to realise that there’s a degradation. Audio is different. You start messing around with audio and it is very, very noticeable. You mightn’t think so, because is the smaller part of the broadcast signal, and has a lower bit rate. But the human ear is very, very sensitive.”