Why do TV ads sound louder and more urgent than the programmes?

Sounds bad
by Russell Brown

Why do TV ads sound louder and more urgent than the programmes? Because they’re heavily compressed. It’s a process that’s also affecting the music we listen to.

It takes only a modest grasp of the technology to realise that the digital files we download from the internet or rip from our own compact discs are inferior in quality to CD sound itself. Such is the reality of the “lossy” compression that reduces the sound files to a manageable size. Information is lost from the recording, and with it, sharpness and dynamic range.

In most cases this doesn’t matter too much, especially if the music is played on small devices (on the other hand, listen to a 128k MP3 file on a high-quality system, against the same track from a CD – you might be shocked). And if we want real range and richness we can always just buy the CD.

Or can we?

I’m indebted to Chris Hart, the founder of Real Groovy Records, for alerting me to a trend that is a hot topic in audiophile circles: the crushing of CD sound.

“CD quality has diminished hugely and a lot of new releases sound so compressed that they are wearying to listen to,” he says. “In fact, I’ve gone back to LPs – the new Lucinda Williams is the latest to hit the platter. And that’s fine for me, but a lot of people don’t have the luxury of 100 tonnes of vinyl in their basement at work!”

Before we explore this question, it’s useful to note the difference between data compression (making files smaller, usually by stripping out information) and audio compression.

The latter is carried out at mastering, the stage where a recording is prepared for production on CD, and it effectively makes the quiet parts of a recording louder. But because the loudest parts of a recording can’t be made any louder without distorting, the difference between the quiet parts and the loud parts – the dynamic range – is reduced. The recording sounds louder overall because the quietest parts are much louder than they were before compression. This is why TV ads sound louder and more urgent than the programmes – they’re heavily compressed.

It doesn’t matter whether you turn the stereo up or down; as a listener you’ve lost the ability to hear the light and shade in the original recording. This can be an advantage on the radio – broadcasters have long used audio compression themselves to make music sound punchier and more immediate on small systems.

With the balance of music-industry revenue shifting away from physical sales towards rights revenue, there is further incentive for the labels to concentrate on CDs that squawk urgently out of TV speakers or sound tolerable in a YouTube clip.

You may already have had the experience of buying a CD on the basis of radio or TV play and finding something irk‑some about it at home on the stereo. I did, with the heavily compressed debut album by the Arctic Monkeys, which seems to have been mastered for MySpace and MTV. You might even say that this music is being processed to function as an ad.

The serious music listeners who care about this usually describe this new listening experience as “tiring” or “wearying” to the ears. They also complain about the other main means of making a “hot” CD – mastering it so loud that the highest levels distort. (The Red Hot Chili Peppers’ Californication album is reckoned to be a particular offender on that score.)

But ordinary consumers probably won’t know or care, and are even quite likely to subjectively prefer a loud CD over a quieter one. Some commentators hold that the hotting-up process began with the heyday of Motown Records, which had its records pressed loud for urgency. Listen to Martha and the Vandellas’ “Dancing in the Street”.

Such are the market imperatives that drive the “loudness war”. The new high-fidelity formats that offer deeper, richer music playback – SACD and DVD-Audio – have basically been flops in the mainstream market. And perhaps we’re simply consuming music more as an environmental factor than a sit-down listening experience.

It still seems a shame that an album recorded in the 1960s and remastered since should sound worse now than it did then. As more than one wag has suggested, perhaps this will prove to be the music industry’s salvation: they’ll start mastering uncompressed versions and invite us to buy the music all over again.