The music mogul suffered a health issue during filming

Simon Cowell has long been known for his acid tongue and cutting remarks, so it came as a surprise during season 18 of when the 63-year-old seemed more subdued than usual.

Rather than adding his opinions to the mix when co-stars Heidi Klum, Sofia Vergara and Howie Mandel commented on auditions, Simon stayed quiet – but it wasn't through lack of interest.

Simon hasn't been talking during season 18 of AGT due to a medical issue, with the father-of-one explaining his situation during an interview with .

"I think what happened was the acid from my stomach literally burned my vocal cords," he said. "So, this doctor came over and put a camera up my nose, down my throat, and I could actually see how badly burnt they were.

"There was so much I wanted to say [about auditions], and I literally could not talk," he added. "We tried writing things. At one point, I used this kind of iPad device where I had things I'd said before. I tried to use Sofía to translate for me, and she deliberately said the wrong things. So, it was just chaos." Watch Sofia misunderstand Simon below...

Simon was unable to speak for a week of the auditions, and he explained it helped him gain a new perspective.

DISCOVER: Simon Cowell talks painful accidents impacting AGT tenure that changed his life 

"For about seven days, I had to sit there and not say anything, so all I could do was just listen to [the other judges].

"And it was very interesting, because they've all got enough confidence now that they have their own preferences. So we probably disagreed more this year, but in a healthy way. You can't be an expert on everything when you judge this show, because of the variety of acts."

MORE: Simon Cowell's son Eric to have baby sibling? All AGT judge has said about expanding family

Simon's had a run of bad health in recent years and in May he reflected on how the incidents, including two bike accidents, changed his life.

"It was painful, it wasn't great," he said on , adding: "However, I was so unfit before the accident. And I didn't know how unfit I was until I had to do all the stuff afterward.

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"And I'm like 'My god!' Things like that I believe happen for a reason," Simon continued, although maintained that he wouldn't be giving up his biking anytime soon.

"I'm still going to stay on my bike, I'm obsessed with these things," he said to the amusement of his co-stars.

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