Amazon may be upping the stakes in their battle against the iPad. According to The Atlantic, Amazon has acquired a voice recognition company of their own, Yap, and may be planning a Siri-like feature to compete with Apple and the iPhone 4S.

The acquisition was seemingly completed in September, but no public announcement has been made by either company, and the SEC filing that Atlantic sources does not mention Amazon, but instead mentions a company called “Dion Acquisition Sub,” who’s headquarters is suspiciously located in a building owned by Amazon.

Yap’s service, still a work in progress at the time of the acquisition, focused on converting voicemail messages to text, but the company also held patents and other intellectual property relating to speech recognition technology.

It’s unclear what Amazon’s intentions behind the acquisition might have been, but whatever Amazon has in store, it seems apparent that they want to keep it as quiet as possible.

I, for one, highly doubt that Amazon will be able to turn Yap’s service into anything resembling Siri without spending a year or two working on it, if that’s even their intention. They may simply be trying to secure patents in an attempt to cause legal trouble with Apple.