Gwen Stefani has ruptured her eardrum

The blonde bombshell was told not to fly with the condition, which can cause hearing loss, itchiness and pain, by her doctor but made sure she issued an apology to guests via a short video that was aired on a screen at the beginning of the event.

The 'Voice USA' judge - who is dating Blake Shelton - said in the clip: "I am so sorry that I cannot attend tonight, but I wanted to send a message of congratulations to Andre Agassi and my very dear friend Ronald Pearlman. I cannot think of anyone more deserving for such a special award. Tonight's gala supports all the work being done at the Cleveland Clinic and Lou Ruvo Center for Brain Health, which is an amazing organisation. Thank you so much for being part of this evening's wonderful cause."

Event organiser Robin Leach then announced that although Gwen was unable to perform, she had sent over an "Oscar and Grammy winning superstar" in her place.

It was later revealed that Jennifer Hudson had agreed to step in at the last minute.

Gwen was meant to play a 30-minute set to guests, who had forked out as much as $1,000 for a ticket, alongside fellow headliner Jon Bon Jovi.

The 'Hollaback Girl' hitmaker isn't the only one who has been through the wars recently as Jon was forced to axe his gig in New York City last week due to bronchitis.

A spokesperson said at the time: "The decision was difficult to make, but made in the interest of delivering the full, powerhouse performance for which Bon Jovi is known."