Let the yapping begin: Amazon.com quietly has acquired a Siri-like speech recognition start-up called Yap.

The e-commerce giant apparently bought the Charlotte-based company in September, but neither company made a public announcement–Amazon's foray into voice control a la Apple's Siri was uncovered by The Atlantic's discovery of an SEC filing

The filing does not even mention Amazon by name. Instead, it shows Yap merging with a company called "Dion Acquisition Sub," whose address is given as 410 Terry Avenue, Seattle, aka Amazon.com HQ.

Yap originally transcribed voicemails much like Google Voice, but the company's technology apparently is much richer than that suggests. Now the company website reads: "NOTICE: On October 20, 2011, Yap Voicemail will be discontinued." The site also provides Yap users with instructions on how to return to their default voicemails.

Igor Jablokov and his younger brother Victor, both in their 30s, founded Yap in 2006 after Victor noticed their teenage sister "texting like crazy" in the car, Igor told Connections eMagazine, the IBM alumni magazine. (Igor is a former IBM'er, working in the company's microelectronics division, which he said allowed him to explore his interest in speech technology.)

Igor, the company's CEO, said Victor "wondered if you could use speech recognition for [texting]. When he challenged us to figure out how to do it, he didn't realize that free-form speech recognition is one of the most arduous tasks in computer science."

Yap's consumer voicemail-to-text service had remained in private beta. In 2007, the brothers launched trials of the company's mobile application. Yap subsequently was a finalist at Silicon Valley's TechCrunch 40, and then was named North Carolina's Early Stage Company of the Year. In June 2008, the company raised a $6.5 Series A round of funding.

"Yap is truly a leader in freeform speech recognition and driving innovation in the mobile user experience," Paul Grim, general partner at SunBridge Partners, said at the time. "It is increasingly clear that the fastest, easiest, and safest way to interact with services on a mobile device is using your voice, and Yap makes this both possible and intuitive."

"We are humbled by the industry's interest in us ever since we unveiled at TechCrunch last year, providing final validation of the need for this innovation in our daily lives," Igor said upon announcing the funding, Yap's co-founder and CEO. ("You have to be partially crazy to be employee No. 1," Igor said in a 2009 speech at Penn State University. He has a 1997 degree in computer science from the school.)

How does Igor's experience at a start-up compare to working for a giant company like IBM?

"I had infinitely fewer resources," he told the IBM newsletter.. "Conversely, I had an expanded ability to make and influence decisions, whether they were good or bad. I liked that."