Mr Benn attended the opening of Tracey Moberly's exhibition

Tracey Moberly created canvases based on Mr Benn's voice - from audio diaries kept by the former Labour MP throughout his political career.

Ms Moberly said she had based the sonograms on her favourite quotes and passages from Mr Benn's diaries.

Mr Benn attended the opening of the exhibition - called Power: Missiles, Miners and Monarchy - in London.

Ms Moberly, from the Rhymney Valley, south Wales, said the peaks and troughs of the left wing politician's distinctive voice were suited to being represented on the two metre-long canvases.

She added: "He has a very BBC sort of voice, sort of English BBC 1950s voice.

"Also, it resonates a calmness - really factually spot on. You can almost see the words."

The works reflect the peaks and troughs of Benn's voice

But Mr Benn told BBC Wales he found it difficult to describe his own voice.

He said: "I don't think you really can be asked to comment on your height, your weight, your shape, your size, your voice - you can't, because it's part of yourself."

BBC NEWS: VIDEO AND AUDIO Listen to Tony Benn

The sonograms are based on a computer representations of key moments on Mr Benn's audio diaries.

The diaries were spoken into a tape recorder over several decades in which Mr Benn was at the heart of UK politics.

Mr Benn said: "These were diaries, late at night when you were terribly tired you set down what had happened.

"It's different from a speech or conversation.

"It was a rather special form of communication, really talking to yourself about what happened."

Ms Moberly said the artworks were aimed at celebrating the life and work of Mr Benn, who recently celebrated his 80th birthday.