Amazon has signed up India's biggest movie star, Amitabh Bachchan, for its Alexa voice assistant in a bid to lure users in the world's second-most populated nation to its services. The 77-year-old Bollywood patriarch's image is ubiquitous across the country on advertisements for everything from hair oil, cement to even a Unicef-backed polio vaccination campaign. Amazon expects his universal appeal to help it take on rivals Apple's Siri and Alphabet's Google Assistant. "The baritone that has enchanted the Indian film industry for over five decades" will be available to the many Indian customers who use Alexa, Amazon said on its India blog on Monday. Users will be able to access "Mr Bachchan's iconic voice on Alexa by purchasing the Amitabh Bachchan voice experience." India, with over half-a-billion smartphones and some of the cheapest data rates in the world, is rapidly adopting voice-enabled services as people take to the internet through voice rather than typing. The market for speech and voice recognition is growing swiftly in Asia's third-largest economy and expected to jump over 40 per cent this year to $58.4 million (Dh214.4m), according to a report by Dentsu Aegis Network's India unit. Bachchan emerged as Bollywood’s biggest superstar in the 1970s and is seen as India’s answer to Robert De Niro or Al Pacino, playing angry-young-men characters battling corrupt establishments. Amazon first used a celebrity voice when Hollywood actor Samuel L Jackson made a debut on Alexa. It has since added professional voice actors who recite Shakespeare, Mark Twain, proverbs and fables. Last year, rival Google Assistant added the voice of US singer John Legend. The dominant Google voice assistant has yet to debut a celebrity voice in India. As with Jackson, Amazon will apply neural speech technology to make Alexa sound exactly like Bachchan no matter what question he is answering without needing to record every word in his voice in the studio. Users can buy Bachchan’s voice as a skill to provide weather updates, recite poetry and give advice.