In a recent article by Steve White, he tells us how to use Visual Studio and Windows 8.1 to take advantage of speech recognition with Cortana in your apps.
One of the strengths of Cortana is its ability to understand and respond to voice commands. The Windows Runtime API enables you to integrate your app with Cortana and make use of Cortana’s voice commands, speech recognition, and speech synthesis (text-to-speech, or TTS).
It is also possible to voice-enable your apps by implementing speech recognition and TTS capabilities.
We have just published a set of new sample apps that show you how to do these integrations. These two samples are for Windows Phone 8.1, and they complement the existing samples for Windows Phone Silverlight.