HRESULT EchoGet(BOOL *pfEchoOn);
Retrieves the state of echo canceling on the incoming audio stream.
· Returns NOERROR if successful, or one of these error values:
E_INVALIDARG
E_OUTOFMEMORY
SRERR_NOTSUPPORTED
SRERR_VALUEOUTOFRANGE
pfEchoOn
[out] Address of a variable that receives the state of echo canceling. The variable receives TRUE if the engine expects echo canceling on the incoming audio stream, or FALSE if the engine expects a clean signal that hasn't undergone echo canceling. When pfEchoOn is TRUE, the engine typically ignores low-level audio signals.
The state of echo canceling indicates whether the signal should be treated as though it has residual signal on it. In general, echo canceling causes the speech-recognition engine to ignore low-level audio signals so that it doesn't attempt to recognize the residual signal of the echo cancellation.