Speaking to the Daily Mail, O'Leary explained that auditioning in front of a panel with their backs to you is intimidating to begin with and then the singers have to deal with the humility of nobody turning around if they aren't liked:

"Everyone who goes on those shows does so to be judged and maybe an even harsher critique is someone not turning around. It is what it is. You can't complain if you don't like what you hear."

Meanwhile, The Voice's vocal coach Jessie J recently spoke out about the perception of female judges and admitted that she's "bored" of all the comparisons:

"I’m always going to be compared to other girls, Cheryl, Tulisa, Nicole Scherzinger, but I’m so bored by it all. When Tulisa and I get together we don’t talk about X Factor or The Voice, or ratings or tactics. We talk about being young, fake tan and make-up!”

Watch coaches from The Voice UK perform Black Eyed Peas' smash hit single 'I Gotta Feeling' below: