An Amazon spokeswoman declined to say how much the company paid for Ivona.
Ivona's technology already supports several features on Amazon's Kindle Fire tablet computers, such as text-to-speech, said Dave Limp, who oversees the Kindle business.
"We look forward to building great products to deliver world-class voice solutions to customers around the world," Limp said in a statement.
Apple's Siri service on its iPhone smartphones allows users to ask questions and it delivers answers, or suggests possible actions. Ivona's text-to-speech technology on Amazon's Kindle Fire HD tablets reads Kindle e-books aloud to users.
"The Ivona acquisition could provide some technology on the Kindle to compete with Siri, although I would argue that Siri has not been all that was expected of it so far," said Kerry Rice, an analyst at Needham & Co.
Ivona could also help Amazon expand its e-book market to more people with disabilities, such as the blind, Rice added.
Ivona already works with organizations that support visually impaired people, including the Royal National Institute of Blind People.
Amazon shares rose 2.2 percent to $274.15 in afternoon trading on Thursday and hit a record $276.65 in earlier action.
© Thomson Reuters 2012