'Clarity' crooner John Mayer has revealed that while recovering from surgery last summer he wasn't allowed to speak and went almost four months without saying anything aloud.

Speaking to Billboard, the singer explained that after having the operation to remove the granuloma from his throat the rules for recovery were very strict so he had to abide by them:

"I probably had contiguously three, maybe four months of not saying a word. The endurance was tough for me, but I started a new life."

Mayer added that he was forced to rely on electric gadgets in order to communicate and it was a tough experience: "I was forced to type on my iPad to communicate anything. It wasn't liberating. Is breaking your leg liberating? No. All complexity is gone when you don't have a choice."

He has since made a full recovery, but admitted that there's always the concern that the condition will reappear so he now visits a doctor regularly as a precaution: "It's hard to believe that I'm healed, but just to make sure, I keep going back (to the doctor) every two weeks for a look, and it's the same - if not better."

Mayer has now confirmed details of a sprawling 44 date tour that will take him across North and South America this summer.

Watch Mayer's music video for 'Something Like Olivia' here: