Mr Zuckerberg said he asked the actor, who was chosen by the public, after an awards ceremony earlier this month.
The Facebook founder coded the AI assistant – called Jarvis, after the butler in Iron Man – for his home. If he decides to release it to the public, people would relate differently to a famous voice than more robotic sounding assistants, tech experts said.
Mr Zuckerberg asked his Facebook followers to pick the voice after building artificial intelligence to help him around the house.
He told tech news site Fast Company that he called Mr Freeman after the actor presented the Breakthrough Awards, a science prize co-founded by Mr Zuckerberg.
“I said, ‘Hey, I posted this thing, and… thousands of people want you to be the voice. Will you do it?'”
Mr Freeman’s answer was “yeah, sure”, he added. Robert Downey Jr, who plays Iron Man, had offered to voice Jarvis, while Arnold Schwarzenegger features as an alternative voice in jokey videos released by Mr Zuckerberg this week.
Experts in human-computer interaction said Mr Freeman, whose roles have included God in Evan Almighty and the narrator in March of the Penguins, would distinguish Jarvis from existing AI assistants.
Celebrity voices add to the “novelty effect” and might make it more enjoyable to interact with an AI assistant, said Dr Simone Stumpf, a senior lecturer at City, University of London.
“If a user is more engaged, then they might also be forgiving of mistakes, interact more – and thus provide more training data for the AI to get it right – and are less likely to abandon it,”
she told the BBC.
Apple’s Siri, Amazon’s Alexa and Google Home are bringing smart assistants into the mainstream.
Morgan Freeman would be a different offering because he is more of a “grandfather figure” than a friend, said Dr Bernie Hogan of the Oxford Internet Institute.
“We do know people project emotions on to theircomputers,” he said. “We’ve been anthropomorphising these things for years.”