Microsoft hopes you'll one day speak to your computer. On Wednesday, the company announced it will acquire Tellme Networks, a maker of voice recognition software, accelerating Microsoft's plans to voice-enable numerous applications and helping the company get a leg up on mobile search by allowing people to use speech to access information.

The purchase price was undisclosed, but if earlier reports of $800 million are correct, it would be the fourth-largest acquisition in Microsoft's history.

Microsoft chairman Bill Gates has spoken for years of the potential of voice as a user interface to access information and applications, and that's exactly Tellme's focus, with products used in directory assistance and by companies like FedEx and Domino's Pizza for customer service. The purchase should bolster plans to embed voice capabilities into Microsoft's own products by, for example, allowing people to use voice to navigate their Outlook in-boxes and make calls via Live Communicator or Windows Mobile users to search the Internet.

"This allows us to advance the state of the art in speech, which has all sorts of potential that is untapped," says Jeff Raikes, president of the Microsoft Business Division. "You're going to see a wide range of communications technology into the fundamental business application and business infrastructure." Longer-term plans include bringing more speech recognition capability into the Windows operating system and continued research into the possibilities of using voice as a method to verify speakers for security purposes.

Microsoft could find that Tellme gives it a competitive advantage in its battles with Google and others for mobile search, as Microsoft says Tellme already handles more mobile inquiries than Google and Yahoo combined. Voice also is a convenient end-around of the problem of small keypads and less time to type on them.

"People on the mobile phone are on the go, typically, they don't want to have to type," says Tellme CEO Mike McCue. "The phone should ask you what you want to do and you should tell it what to do." For example, users of Tellme's Java-enabled mobile platform can do things like ask a device to find "pizza," see a list of local pizza places pop up on the screen, and tell the device which one to call.