vb.net capture system audio to stream

Is it possible to capture all/any audio played by a PC into a system.io.stream, so that it can then be run through speech recognition (System.Speech.Recognition.SpeechRecognitionEngine)?

Essentially I'm looking to pefrom speech recognition on any a开发者_如何学编程udio on the client PC, google seems to suggest that capturing a stream like this can be done using Microsoft.DirectX.DirectSound, however I cannot honestly determine how. Any suggestions would be greatly appreciated.

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Take a look at this question for a solution on Vista/Win7, and take a look at this one for WinXP.

Summary: You can use Loopback recording with WASAPI in Vista/Win7, but there is no equivalent API in WinXP, however a partial solution can be achieved with a virtual soundcard driver.