In an interview with British comedian Dara O'Briain, legendary physicist Stephen Hawking's son Tim admitted he would prank his father as a child by programming his voice box with curse words and using Hawking's wheelchair as a go kart.
Hawking was diagnosed with amyotrophic lateral sclerosis (ALS) when he was 21, a disease which has caused him to slowly lose control of various parts of his body -- including the majority of his mouth.
CBS Washington's Benjamin Fearnow reports:
Tim, who currently works in marketing for the toy company Lego, said at one point he placed curse words into his father’s speech machine as a prank, would use his father’s wheelchair as a go-kart and would often have intense board game battles with his “hugely competitive” father – particularly long games of chess.
In the documentary interview, Tim discussed the emotional impact of finally being able to communicate with his father after he received his speech device.
Hawking lost his natural voice completely after a tracheotomy following a bout with pneumonia.
"My dad was able to speak with his own, natural voice for those first years, but it was incredibly difficult to understand what he was saying, particularly for me at such a young age," said Tim in a BBC1 documentary. "As a three-year-old, I had no understanding of what he was saying. I didn't really have any communication with him for the first five years of my life."
"It was only when he got his voice synthesizer that I was actually able to start having conversations with him," he continued. "It was somewhat ironic that Dad losing his voice was actually the start of us being able to form a relationship."