Gwen Stefani still gets nervous before performing live.

The No Doubt frontwoman and solo artist has been in the business for years, but still get apprehensive before taking to the stage. But it's this fear that has enabled her to relate more to her nervous contestants on The Voice as they take part in the live eliminations on the TV talent show.

"It's been all these years and I still, when I do live music... I still get nervous. It's crazy," she told Entertainment Tonight in an interview with her fellow judges Adam Levine, Alicia Keys and Gwen's boyfriend Blake Shelton. "Anything can happen, you know? It's that adrenaline. It's amazing, I love it. I get the beating heart, you know what I mean? I can't imagine what they (the artists) feel like."

"They're probably petrified," Adam agreed.

With three seasons of the show as a judge on the NBC singing competition under her belt, Gwen believes that the key to success isn't just down to the contestant's voice and talent - but what is in their heart.

"I just keep telling my team, 'At this point, you've already proven that you're great singers and performers. At this point, it's really just opening up your heart and letting people in to get to know you,'" the mother-of-three explained. "I think that's what we are attracted to as fans of music, is being able to connect. It's hard to do that when you're on TV doing a performance and there's a lot to learn about being on TV and doing performances, so we talk about that. It's something that's hard to learn in a short amount of time."

However, her boyfriend and judging rival, country star Blake, refused to give away any of the techniques that may help him win the twelfth season of the show.

"Now is when I switch into my winning strategy, and you know I can't give those secrets away," he joked. "I did look ahead at this year's script and they have me winning again."