In total the deal is worth approximately $293m, based on Monday’s closing price of $15.28 per share of Nuance common stock. The transaction is made up of 5.8 million shares of Nuance common stock and a net cash payment of $204m.

Until a few years ago it was known as ScanSoft but changed the name when ScanSoft purchased rival speech software maker Nuance Communications in May 2005 in a deal worth $221m. The merged company rebranded itself Nuance, and since then the Burlington, Massachusetts-based company has continued to acquire at an impressive rate.

In February 2006 it boosted its voice-recognition credentials after agreeing to pay $357m in cash for Dictaphone, a Stratford, Connecticut-based company that made dictation and speech software primarily for the healthcare industry, helping convert doctors’ recorded dictation about patients into electronic transcripts.

In December 2006 Nuance acquired a small mobile speech-recognition company for an undisclosed amount. Privately held MobileVoiceControl, like Nuance, offered voice dictation services for mobile handsets.

And 2007 did not see any slowdown in Nuance’s acquisition drive. In February it paid up to $200m for BeVocal, which offered self-service customer care geared to the mobile communications market. A month later in March, Nuance paid $58m in cash for Focus Infomatics, as a way to expand its healthcare transcription services.

And in now its third acquisition in 2007, Nuance said it will acquire VoiceSignal Technologies. Nuance said that with the addition of VoiceSignal, it expects to deliver mobile device control and voice search to a billion consumers within next three years. The company also anticipates that its total mobility revenues will exceed $125m in fiscal year 2008.

“Today, more than 2 billion people worldwide rely on mobile phones to stay connected, informed, and productive,” said Nuance CEO Paul Ricci. “We see an expanding opportunity in helping consumers to use the powerful capabilities of their phones and to access the array of content and services available on the mobile Web.”

Looking at the client base of the combined company, it is not hard to see the reasons for Ricci’s optimism. Mobility customers include AOL, AT&T, DaimlerChrysler, Ford, Kyocera, LG, Motorola, Nokia, Palm, Rogers Wireless, Samsung, Sanyo, Sony Ericsson, Sprint, RIM, T-Mobile, Toyota, and Vodafone.

Nuance said the transaction is expected to close in the fiscal fourth quarter, subject to the usual closing conditions and regulatory approvals. It also expects VoiceSignal to contribute between $40m and $42m in GAAP revenue in its fiscal year 2008, along with a loss between $0.04 and $0.05 per share.

The combination is expected to generate approximately $8m to $10m in cost synergies in fiscal year 2008, although it didn’t say where this would occur.

Shares in Nuance rose 3.27% to $15.78 on Nasdaq on Tuesday.