In keeping with its buy-small-and-keep-it-quiet acquisition policy, Apple (AAPL) has purchased U.K.-based Novauris Technologies, an automatic speech recognition (ASR) software developer the vendor will use to improve its Siri speech-based virtual assistant service.

Terms of the deal were not disclosed and Apple issued its standard non-confirmation confirmation, saying “Apple buys smaller technology companies from time to time, and we generally do not discuss our purpose or plans.”

But wait, there’s a twist to this Apple acquisition. On the surface, it appears as though Apple pulled the trigger on the Novauris deal in the wake of Microsoft’s (MSFT) Windows Phone 8.1 Cortana announcement at its recent Build 2014 conference. Not so, according to Tech Crunch—the transaction actually took place last year but remained undiscovered. Apparently, the Novauris team has been at Apple since last fall working on improvements to the vendor’s Siri technology, Tech Crunch said.

Hmmmm, Apple gets a gold star for keeping this news quiet. Even Novauris remained mum on the subject, mentioning nary a word on its website. It took Novauris co-founder Melvyn Hunt confirming to Tech Crunch that he and his cohorts are part of Apple and have been working on Siri to put the mystery to rest.

The 12-year old Novauris was run by chief executive Yoon Kim and co-founders Hunt and John Bridle, whose backgrounds include Dragon Systems, Nortel, SRI, Marconi and Aurix. Hunt and Bridle are recognized internationally as pioneering speech researchers. Dragon developed the popular DragonDictate and Dragon NaturallySpeaking products.

Novauris’ customers included big names such as Alpine, BMW, Panasonic, Samsung and Verizon Wireless. The company produced a demo app in 2011 called “Speak&Go London,” a speech recognition guide to London for mobile phones.

Cortana, Microsoft's new virtual personal assistant, now is a Windows Phone 8.1 feature. Users can interact with it either through speech or typing and the technology ultimately will be tied to other Microsoft apps such as Skype.