|Microsoft DirectX 9.0|
Microphone setup is supported by the Microsoft?DirectX?Voice Test Wizard. This wizard confirms that your system properly supports full duplex operation and ensures your microphone and playback settings are correct. You need to run the wizard only once for each combination of playback and capture device you select.
You can launch the Voice Test Wizard in two ways:
Each time your application starts, you should test the configuration by calling IDirectPlayVoiceTest::CheckAudioSetup with the dwFlags parameter set to DVFLAGS_QUERYONLY. This enables you to quickly test whether the device configuration has changed since you last tested them. If your devices have not been tested, you should run IDirectPlayVoiceTest::CheckAudioSetup again to invoke the wizard. If you do not do so, IDirectPlayVoiceClient::Connect will return DVERR_RUNSETUP, and you will not be able to initialize Microsoft DirectPlay?Voice.
Many older computer systems still in use do not have a full duplex sound card. Without full duplex, a sound card can receive—but not send—voice communications. Because games typically hold the sound card in playback mode, DirectX prevents problems by not allowing dynamic switching between playback and capture. The Voice Test Wizard provides users with information about the duplexing abilities of their system.