Adam Levine fears there are “problems” with The Voice.

The Maroon 5 rocker is one of the judges on the US reality show, at the moment joined by Blake Shelton, Pharrell Williams and Gwen Stefani. The seventh season of the programme will air later this year, with Adam only too aware that changes need to be made.

“I’m not going to lie to you, I think there are problems,” he told Rolling Stone.

For Adam, the main issue is finding an up-and-coming singer who will resonate with the public. While shows like American Idol and The X Factor have managed to launch huge careers for people such as Jordin Sparks and Jennifer Hudson, The Voice has not managed to follow suit.

“Millions… watch the show every week and fall in love with a singer, then you don’t hear much from them. We haven’t had a breakout success like Kelly Clarkson or Carrie Underwood,” Adam explained.

“[The show is] very successful, but it’s got a ways to go.”

When it launched, The Voice’s unique selling point was the blind auditions. Wannabes took to the stage to perform with the mentors sitting in huge chairs with their backs to them. The judges only got to see the contestant if they blindly chose to put them through to the next round, or if they didn’t make it in which case the chairs would swing around anyway.

It’s not just in the US that the show has faced issues, despite having stars such as Sir Tom Jones and on the panel in the UK it has also failed to launch anyone to superstardom.

US show bosses will likely be hoping that newcomers Gwen and Pharrell will give the show a new lease of life, with Adam previously admitting he is thrilled to welcome them on board.

“I’ve been a fan of Gwen’s and Pharrell’s for so long - they’re both such inspirational people,” he told EW. “They’re incredible, and it’s such a score to be able to get them on this show.”