Speaking to the radio times, the Welsh pop legend said: "I feel like I know what I am doing this time and it feels more natural.
"Last year we were given suggested lines just in case we got stuck, which I tried to work in on a few occasions."
The crooner said the comments were not him, and made him feel self-conscious.
Sir Tom returns with fellow coaches Jessie J, Will.i.am, and Danny O'Donoghue for the second series of the show this weekend.
Jessie J, Sir Tom Jones, Danny O'Donoghue and Will.i.am will be competing against each other on the BBC talent show, which is set to have some new twists this time round.
The show's ratings dropped during the first series following the end of the "swivel chair" rounds.
An 11-date tour featuring performances from the finalists was cancelled, due to poor ticket sales.
Leanne Mitchell, who was mentored by Sir Tom won the show last year, but a download version of her debut single failed to make it big in the charts.
All four coaches will return for the second series of The Voice, the BBC announced today.
Sir Tom Jones, will.i.am, Jessie J and Danny O'Donaghue will once again take their swivelling seats for the new shows, which are to be aired in Spring 2013.
Leanne Mitchell won the 2012 series, which broke records to become BBC One's most watched new entertainment series.
will.i.am said: "This season is gonna be doper than last year!"
People power ensures The Voice access to the Olympic stadium: A big thank you to all who supported the cause! http://t.co/lY5s6wGa
Will.i.am stressed the importance of nurturing creativity from young people from inner cities today, as he donated £500,000 to the Prince's Trust. He said there was a large resource of musical creativity around London that should be channelled to build work skills.
"I grew up in east Los Angeles, one of the most under-served and tough neighbourhoods in America. My family made sure I understood that getting a good education and hard work were key to turning my dreams into reality and beating the odds that come with growing up in a disadvantaged situation."
"The Prince's Trust has a 36-year history of assisting disadvantaged youth, so I am pleased to be collaborating with an organisation that shares my mission to transform the lives of young people who need extra support and structure in their lives."
Leanne Mitchell has won the first series of BBC singing competition The Voice.
Mitchell, mentored by Sir Tom Jones, looked stunned after the result of the public vote was announced in tonight's live show and said: "I am starting to believe in myself."
She beat Tyler James, mentored by Will.i.am, and Bo Bruce, mentored by Danny O'Donoghue.Vince Kidd, coached by Jessie J, was eliminated earlier in the show.
Simon Cowell has criticised talent shows that are a "bad copy" of The X Factor and said he was "puzzled" by BBC show The Voice.Read the full story ›
Kylie Minogue and Cheryl Cole are among the stars lined up for guest appearances on BBC1's The Voice as the show battles a ratings slide.
The addition of the two chart stars comes as the programme suffered a further audience blow for its results show on Sunday - losing two million viewers in a week.
On Saturday Britain's Got Talent beat The Voice for the second week in a row.
Hannah Berney and Ruth Ann St Luce have become the latest contestants to be ejected from The Voice. Five artists from mentor Jessie J's team sand on last night's live show, along with five performers from Danny O'Donoghue's team.
After hearing the news Hannah, from Chepstow, nodded before hugging Max and saying: "This has probably been the best year of my life, I turned twenty one, I've sung for the Queen, I've done live television. I know what I'm doing with my life."
Ruth Ann looked dejected when she heard the news, saying: "It's been a crazy rollercoaster doing this show, I've learned so much from Jessie - in fact from all of you guys, some of the comments you've made and said to me have been life changing. This is not the end."
The Voice star Matt Fletcher has revealed he refused to bow to pressure from BBC bosses to shave his beard because he feels it is the source of his power.
He said: "They were talking about taking off the whole beard, but it's a part of me and I lose my power without it."
He added: "They did try and I said something like 'I think I could take two or three of you down before you pin me down and shave it, but if you want to go for it, go for it', and they backed off."