Sometimes it’s subtle – and often it’s not – but now that The X-Factor is using Auto-Tune to boost contestants, millions are familiar with the infamous trick of the trade

THE TV steamroller that is The X Factortrundled back on to our screens last weekend. Every year, it brings another format tweak, a slew of PR-friendly news stories or a relatively minor controversy. All are happily present this year (Cheryl and Simon are fighting, Louis hates RTÉ), but it was the show's technology that saw people pounding their keyboards and leaving angry messages on X Factorforums and Twitter. This series, contestants at the live studio auditions are having their vocals digitally manipulated.

It seems people don't mind the show's producers embellishing back stories and scripting interaction between panel and hopefuls (remember SuBo?). The irony of the outrage is that audiences will accept the soap plot lives of contestants being tinkered with, but not their actual voices. Why tweak them? It is, after all a singing competition, and one that costs money to cast a vote in. And X Factoraudiences are just as happy to indulge in the schadenfreude of laughing at bad singers as they are to whoop delightedly when someone successfully belts out a big tune.

Last Saturday, it was clear that Gamu Nhengu could sing, even if her version of Walking on Sunshinewas unconventional. The addition of Auto-Tune actually spoilt a great performance. It anaesthetised the emotion, adding a robotic flourish to a soulful voice that didn't need it.

Perhaps it's all Cher's fault. In 1998, sporting a headful of feathers in the video for the single Believe, her vocals sounded as if she was walking a tightrope in high winds while trying to keep her balance. It was a very deliberate vocal tic, albeit an artificial one, called Auto-Tune.

Created as pitch correction software for those blessed with less than perfect pitch, it was initally a guilty production secret, but a widely used "plug-in" in most recording studios. Post-Cher, it was a much-copied novelty effect which quickly became unfashionable, only to be resurrected in the last couple of years. The rap, pop and R'n'B community have embraced its spacey note-bending with gusto, with singers like Rihanna, Lady Gaga and Kanye West employing it on songs. Rap grandmaster Jay-Z also experimented with it, only to denounce it – how else? – with last year's single Death of Auto-Tune.

We can blame Cher for questionable wardrobe choices over the years, but not for Auto-Tune. It was created by Andy Hildebrand, who oddly, is not a compressor-obsessed studio nerd who alphabetises his microphone brands, but an ex-oil engineer. He originally used a variation on Auto-Tune to calculate drill sites for Exxon. Retired and obscenely wealthy, he was challenged by a friend at a dinner party to create a device that would help her to sing in tune.

The result was something that producers Stock, Aiken and Waterman would have killed for in the 1980s when their assembly line of soap stars and pop kids dominated the charts. Contrary to popular belief, what they did wasn’t autotuning, as Hildebrand had yet to invent it. Instead, the trio would double-track weak vocals and use “panning”, where two copies of the same vocal track are placed in each stereo speaker to “thicken” vocals.

Pop and rap are Auto-Tune’s spiritual home, but it has been adopted by other musicians, often ironically, but usually as a natural extension of their sound.

For Canadian folk minimalist Bon Iver, it is the antithesis of his songs-recorded-in-a-remote-log-cabin repoirtoire, but his track Woodsplayfully revels in its eerie bends and swoops.

It was less of a leap for French dance duo Daft Punk, who used it their floor-filling hit, One More Time. More recently, it turned up on a breezy Vampire Weekend track, Californian English, and bandmember Rostam Batmanglij used lots of Auto-Tune vocals on his side project, Discovery. All are established artists. X Factorcontestants are not, and what is being presented to the audience makes it harder to judge who the genuinely talented singers are.

Producer Rick Rubin (who was responsible for urging Johnny Cash to cover Will Oldham, U2 and Nick Cave on American Recordings: Solitary Man) says he sits down and has an "ethical talk" with the artists he works with, encouraging them to ditch Auto-Tune.

Perhaps X Factorneeds to adopt a similar policy. We all know that the show is not a particularly level playing field, but now evenness – and the show's minimial credibility – oscillates like the vocals of its latest round of auditionees.

Other voices

The Good

Bon Iver Woods

A haunting ballad that manages to retain its heart despite the chilly robotic effects.

The Bad

Dane Bowers and Victoria Beckham Out of Your Mind

Derisory snorts about Posh’s vocal abilities are nothing new, but they bent gymnastically on this duet.

The Best

Daft Punk One More Time

The French pair had experimented with vocoder vocals on Around the World, but went all out on the Auto-Tune front with one of their biggest hits.