Rocker John Mayer cried after learning his doctor would be sticking a long needle in his neck to treat his voice problems without the use of an anaesthetic.

The singer/songwriter, who struggled with throat problems for a few years, had to have muscle freezing agent Botox injected into his vocal cords to cure his ongoing issues, but he admits he was wracked with nerves at the thought of having the procedure done while he was wide awake - and he didn't even need to be admitted to hospital for the operation.

He explains, "I met this great doctor and he said, 'We just give you Botox'. I said, 'What day would that be?' and he goes, 'We can do it right now' and I said, 'So would you put me under (anaesthetic) and then you would put that (the needle) down my throat?' And he goes, 'Nope, we go right in through the neck' - and I started crying. I was just trying to tip my head back so the tear wouldn't break the surface, and then I was like, 'Ok...'"

Mayer confesses the tough news was even harder to take as he knew he would be banned from speaking for months after the operation. He spent four months without uttering a word as his vocals recovered, but the difficult experience has made him all the more appreciative of his gift.

He tells U.S. talk show host Ellen DeGeneres, "I just have so much more respect for singers, and have finally come around to calling the voice an instrument... We always used to roll our eyes when people said it was an instrument, but it is. It's really sensitive, people book months and months and months ahead to tour and you play for thousands and thousands of people from this tiny, tiny, little muscle and so I have so much more respect for it and so much more respect for playing music. I want to just enjoy everything now."

The Your Body Is A Wonderland hitmaker returned to the stage for the first time since the August (12) operation in January (13) and recently announced plans for his first tour in three years.