Apple endowed its virtual personal assistant Siri, exclusive to the iPhone 4S, with different voices to accommodate different languages and dialects. Apple calls the UK version of Siri Daniel, but the voice talent behind Daniel didn't know he was the voice of Siri until he saw it displayed on television.

I did a set of recordings with Scansoft five or six years ago, for text-to-speech services, said Jon Briggs, a former technology journalist, and the male voice of UK Siri, a.k.a. Daniel. Five thousand sentences over three weeks, spoken in a very particular way and only reading flat and even. Then they go away and take all the phonics apart, because I have to be able to read anything you want, even if I've never actually recorded all those words.

Originally a third-party iPhone application born from SRI's CALO project, or Cognitive Assistant that Learns and Organizes, Siri was the largest artificial intelligence project in U.S. history. The Defense Advanced Research Projects Agency (DARPA), which provides advanced research for the U.S. Department of Defense, invested $150 million into CALO over five years.  

After years of development, Siri can now help any iPhone 4S owner create and send off texts and e-mails, set alarms and reminders, schedule meetings, place calls, surf the Web, dictate notes, play songs, and even answer context-sensitive questions. Siri requires no training on the user's part.

Briggs had no idea that his voice talents, recorded six years ago, would later become the voice of Apple's iPhone 4S. The company that hired Briggs, Scansoft was with Nuance Communications in 2005. Nuance, based in Burlington, Mass., is also responsible for speech recognition services Dragon NaturallySpeaking and Dragon Dictate. Reports said it worked with Apple in developing Siri.

[Siri is] as close to human speech as anything that's out there, Briggs said. It gets everything right, more or less, apart from the inflection.

Brigg's voice is the only male voice available in UK English. He only discovered his role in Apple's new product when he saw Siri being demonstrated on television. But Briggs isn't bitter.

I got paid a decent sum by Scansoft, Briggs said. I love Apple's products and I think Siri is a game-changer.

Apple, based in Cupertino, Calif., did reach out to Briggs once, asking him not to talk about Siri.

We're not about one person, Apple reportedly told Briggs.

Briggs complied, even though his contract was signed with Scansoft, and not Apple. Since that single communication, Apple has not been back in touch.

You're not allowed to license the voice to make money, Briggs said. So Apple's Siri is part of the service once you've bought the phone.

Briggs has used his voice for countless projects, including BBC's Radio 2, The Weakest Link, and he's also the voice of satnav for Garmin, TomTom, Audi, Porsche, Jaguar and Land Rover. He loves that his work for Daniel suddenly enfranchises a whole group of people who, for whatever reason, can't type.

He's further entertained by the actions of Google chairman Eric Schmidt, who, in a letter to Congress, called Siri a threat.

This is really a clever idea, Briggs said. I'm amused to be part of the fabric of things.

Siri's sophisticated technology is such that Nuance and Scansoft will never need Briggs to record any more Daniel. He may not be needed for any more voice work, but Briggs is not worried about being replaced.

Voice defines how you think about somebody; age, sex, educational background, Briggs said. So changing Daniel would be more than about technology.