The second series of the BBC One show will see four musical coaches – Jessie, Will.i.am, Danny O’Donoghue and Tom Jones – build up teams of singers by pressing buzzers to signal they want a hopeful, based purely on their voice.
However the hip hop star revealed how she had been "very picky" with the contestants, criticising budding performers for their poor diction and breathing.
"My mum taught me a lot of breathing and diction techniques, they're so important," she explained last month. "I practice each day... that's why I have such a big mouth!"
But Jessie confessed she is too critical with some singers, and that she's regretted not pressing her buzzer during their audition.
"I've missed so many people I should've pressed the buzzer for," she added.
The Voice UK 2013 will launch on BBC One at the end of the month.