Prime Minister Tony Abbott is putting his money where his mouth is when it comes to his mantra to be ''methodical, measured and calm'', a voice expert has found.

In fact, Mr Abbott speaks 100 words a minute slower in media interviews than he did in opposition, and also speaks in a more monotone voice, according to Cate Madill, the director of the voice research laboratory at the University of Sydney's faculty of health sciences.

She reviewed interviews and news conferences from Mr Abbott's time as opposition leader, his election victory speech, and his interaction with the media and Parliament since then.

Dr Madill said changes in his delivery were ''absolutely significant'' and the result of coaching.

''Since he's become Prime Minister, his speech rate has dropped considerably,'' she said.