|Microsoft DirectX 9.0|
The Full Duplex Filter sample application shows how to capture and play back sounds at the same time.
Source: (SDK root)\Samples\C++\DirectSound\FullDuplexFilter
Executable: (SDK root)\Samples\C++\DirectSound\Bin
Be sure your sound card is configured for full-duplex operation and that you have a microphone attached. Choose a format from the Output Format list. A list of formats appears in the Input Format list. Select one. Click OK. If full duplex is successfully created, another dialog box is displayed with a Record button. Click this button. Speak into the microphone and your voice is heard over the speakers.
The sample does not use the DirectSoundFullDuplexCreate8 function, which is not supported on earlier operating systems. Note that the DirectSound device is created before the DirectSoundCapture device.