JFK gives final speech - 55 years after his death

A speech John F Kennedy was due to deliver in Dallas on the day of his assassination has been recreated with recordings of his voice.

Mr Kennedy's rebuke of populist politics was due to be delivered at the Dallas Trade Mart on 22 November 1963 - the day he was killed while travelling in his motorcade.

Paper copies of the speech survive, but now software engineers at CereProc, a British audio technology company, and Irish creative agency Rothco, have teamed up with The Times to create a recording of JFK delivering the speech.

The speech, which is 2,590 words long, was created with 831 recordings of Mr Kennedy's speeches and radio addresses.

Engineers took 116,777 sound units, which enabled them to reproduce his speaking pattern and cadence.

Chris Pidcock, the chief voice engineer at CereProc in Edinburgh, told The Times that the project required two months of painstakingly creating a database of the best-quality recordings of the president's voice.

This database was used to train an algorithm to apply his intonations and voice characteristics to words.

"To predict his intonation we analysed the way he speaks by pitch and duration of sounds and the energy he puts into various sounds depending on where they are in a sentence," said Mr Pidcock.

The recording is convincing, and does not sound as if it has been patched together from existing sound clips.

John F Kennedy was 46 when he was assassinated

That is because the audio units which the team collected were used to train an algorithm to replicate how Mr Kennedy spoke, rather than cutting them together in a form of audio collage.

Mr Kennedy's words, on the risks of populism, seem appropriate for today, 55 years after they were due to be given.

"Ignorance and misinformation can handicap the progress of a city or a company, but they can, if allowed to prevail in foreign policy, handicap this country's security," the speech says.

"In a world of complex and continuing problems, in a world full of frustrations and irritations, America's leadership must be guided by the lights of learning and reason - or else those who confuse rhetoric with reality and the plausible with the possible will gain the popular ascendancy with their seemingly swift and simple solutions to every world problem."

(SKY NEWS)