HRESULT AutoGainEnableGet(DWORD *pdwAutoGain);
Retrieves the state of the automatic gain for the incoming audio stream.
� Returns NOERROR if successful, or one of these error values:
E_INVALIDARG
E_OUTOFMEMORY
SRERR_NOTSUPPORTED
SRERR_VALUEOUTOFRANGE
pdwAutoGain
[out] Address of a variable that receives the automatic gain.
A value of 0 indicates that automatic gain is disabled. A value of 100 indicates that the speech-recognition engine always adjusts the gain, so that if the next utterance is spoken at the same level, the gain is set perfectly. A value between 0 and 100 moderates the automatic adjustments on a linear scale. For example, a pdwAudioGain value of 50 adjusts the gain to half the extent that the engine otherwise would.
When automatic gain is enabled, the speech-recognition engine may adjust the level at the end of an utterance and increase or decrease the gain. The engine adjusts the gain by using the IAudio::LevelGet and IAudio::LevelSet member functions to communicate with the audio-source object that represents the incoming audio stream.
If the audio source does not support IAudio::LevelSet, the application cannot set the automatic gain.