John F Kennedy's lost speech brought to life

President Kennedy was assassinated in Dallas on 22 November 1963

The voice of John F Kennedy has been heard for the first time giving the speech he was due to deliver on the day he was assassinated.

The 46-year-old was on his way to the Dallas Trade Mart to address the Citizen's Council when he was shot and killed on 22 November 1963.

Edinburgh company CereProc used audio and text from 831 of his speeches to recreate his words from that day.

They were able to reproduce all 2,590 words from the 20-minute speech.

The company said it took them eight weeks to put the speech together, during which JFK discusses America's standing in the world and the cost of maintaining its security.

The project to create the recording was commissioned by Irish company Rothco and completed in partnership with The Times newspaper.

CereProc said that they analysed recordings of hundreds of JFK's speeches and split them into smaller "phonetic units" to reproduce the 55-year-old speech.

He had been due to give a speech at the Dallas Trade Mart when he was killed

Lead voice engineer Chris Pidcock told Radio Scotland's John Beattie programme: "We use machine learning and artificial intelligence techniques just to try and figure out how he moves his pitch and the duration of his sounds through his sentences.

"That was a big part of the project because we didn't want his intonation to be a boring and standard intonation.

"We took his existing speeches and material and we cut it up into tiny pieces and stitched it back together into a new speech.

"JFK had a really unique speaking style and getting his intonation correct was something that we had to spend some time on."

The company said the technology would be used in future to help those losing their voices through illness or accident so that they could retain their own individual sound and avoid the robotic tones associated with the late Stephen Hawking.