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Gamu Nhengu's audition was one of many where autotuning was obviously used. ITV
The X Factor

How The X Factor's autotuning really works

Get to grips with the software behind the controversial audio-polishing technique.

THE PRODUCERS of The X Factor have come under criticism for using auto-tuning software to make some auditionees sound better than others.

The show’s makers say it’s standard practice, explaining that the singers auditioning for the programme use different microphones and that the work helps the work sound more uniform.

But viewers watching the show quickly noticed that some singers’ voices sounded curiously robotic – a tell-tale sign of auto-tuning software being used, presumably making good auditionees sound better so that the lesser ones suffer by comparison.

So how does the software work? Well, basically it takes the audio clip – in this case the singer’s vocal track – and slices it up into tiny segments.

Chopping and changing

The musical scale has twelve notes in it, all of which have very specific audio frequencies. What the software does is take the tiny segment, analyse what frequency the singing is, and then nudge it up or down until it’s exactly equal to the ‘proper’ frequency.

It then strings all of the individual chunks together – which is where the tell-tale robot sounds come from. Instead of gliding between notes the way a regular voice does, the final clip will have more mechanical jumps between notes.

More sophisticated autotuning software can recognise a deliberate slide between notes (known as a glissando in musical parlance) but it’s not yet possible for an artificial mind to discern when a slide is artistic or when it’s just a bum note.

Hence, the final clip is slightly clipped – as demonstrated in Gamu Nhengu’s audition, where the audio seems to make a popping noise between C and D notes about 22 seconds in, as she sings the word ‘sure’; and again in the first line of the second verse from 50 seconds in:

The software, as it turns out, is quite cheap – in fact, you can get plugins for the free Audacity audio editor that’ll do it for you – so it’s quite possible that the future generations of home-schooled musicians will be reliant on such technology.

If you’re bothered, in the meantime, you can join any number of Facebook groups and pages in protest at the practice.