Last reviewed: 3/23/2024 9:34:16 AM

Event Handling

To track the progress of backup and restore operations, applications receive event notifications. Event availability varies among Speech APIs.

EventEvent ArgumentsDescription
ApiErrorChantAPIErrorEventArgsNotifies the application of an API error
AudioSourceStartAudioEventArgsNotifies the application the speech recognizer has started processing audio
AudioSourceStopAudioEventArgsNotifies the application the speech recognizer has stopped processing audio
FalseRecognitionSREventArgsNotifies the application the speech recognizer was unable to recognize speech from the utterance
InterferenceInterferenceEventArgsNotifies the application the speech recognizer detected interference
RecognitionRecognitionEventArgsNotifies the application the speech recognizer recognized speech
SoundSREventArgsNotifies the application the speech recognizer detected sound
UtteranceBeginSREventArgsNotifies the application the speech recognizer detected the beginning of an utterance
UtteranceEndSREventArgsNotifies the application the speech recognizer detected the end of an utterance

Some events provide data values that are returned in argument objects. Argument data availability varies among Speech APIs.

  • AudioEventArgs
    • File - File name
    • AudioStreamOffset - Audio stream offset
    • AudioTimeOffset - Audio time offset
  • ChantAPIErrorEventArgs
    • Function - API funtion name
    • Message - API error message
    • RC - API error return code
  • InterferenceEventArgs
    • Interference - The type of interference detected by the recognizer
    • AudioStreamOffset - Audio stream offset
    • AudioTimeOffset - Audio time offset
  • RecognitionEventArgs
    • Text - Recognized speech
    • Property - Recognized speech property value
    • AudioStreamOffset - Audio stream offset
    • AudioTimeOffset - Audio time offset
  • SREventArgs
    • AudioStreamOffset - Audio stream offset
    • AudioTimeOffset - Audio time offset

Event notifications are recieved in callback routines as follows:


if (_Recognizer != null)
{
    _Recognizer.APIError += this.Recognizer_APIError;
}


// Static event handler declaration
void CALLBACK APIError(void* Sender, CChantAPIErrorEventArgs* Args);
...
if (_Recognizer != NULL)
{
    // Optionally, register Event Handler
    _Recognizer->SetAPIError(APIError);
}
    

// Static event handler declaration
void CALLBACK APIError(void* Sender, CChantAPIErrorEventArgs* Args);
...
if (_Recognizer != NULL)
{
    // Optionally, register Event Handler
    _Recognizer->SetAPIError(APIError);
}
    

if (_Recognizer <> nil) then
begin
    // Register Event Handler
    _Recognizer.APIError := APIError;
end;
    

_Recognizer = _ProfileKit.createSAPI5Recognizer();
if (_Recognizer != null)
{
    // Optionally, set the callback object
    _Recognizer.setChantProfileKitEvents(this);
    // Optionally, register for callback
    _Recognizer.registerCallback(ChantProfileKitCallback.CCAPIError);
}
    

_Recognizer = _ProfileKit.CreateSAPI5Recognizer()
// Declaring the event handlers routines with Handles clause in VB automatically registers for the event notifications
Private Sub Recognizer_APIError(ByVal sender As System.Object, ByVal e As ChantAPIErrorEventArgs) Handles _Synthesizer.APIError

The recognizer object send all notifications to the event handlers. All event data is contained in a arguments object.


private void Recognizer_APIError(object sender, ChantAPIErrorEventArgs e)
{
    // Format transcript message
    string errorMsg = "";
    errorMsg = "(" + e.RC.ToString() + ") ";
    errorMsg += " " + e.Function.ToString() + " ";
    errorMsg += e.Message;
    ...
}
    

void CALLBACK APIError(void* Sender, CChantAPIErrorEventArgs* Args)
{
    // Format transcript message
    CString strErrorMsg;
    strErrorMsg.Format(L"(%d) %s %s\r\n", Args->GetRC(), Args->GetFunction(), Args->GetMessage());
    ...
}
    

void CALLBACK APIError(void* Sender, CChantAPIErrorEventArgs* Args)
{
    // Format transcript message
    String strErrorMsg = "(" + IntToStr(Args->GetRC()) + ") ";
    strErrorMsg = strErrorMsg + " " + Args->GetFunction() + " "  + Args->GetMessage() + "\r\n";
    ...
}
    

procedure TForm1.APIError(Sender: TObject; Args: TChantAPIErrorEventArgs);
var
  strErrorMsg: string;
begin
      strErrorMsg := '';
      strErrorMsg := '(' + IntToStr(Args.RC) + ') ';
      strErrorMsg := strErrorMsg + ' ' + IntToStr(Args.Function) + ' ' + Args.Message +  #13 + #10;
      ...
end;
    

public void apiError(Object sender, ChantAPIErrorEventArgs args)
{
    System.out.println(
        String.format("(%d) %s %s", args->getRC(), args->getFunction(), args->getMessage())
    );
}
    

Private Sub Recognizer_APIError(ByVal sender As System.Object, ByVal e As ChantAPIErrorEventArgs) Handles _Synthesizer.APIError
    Dim errorMsg As String
    ' Format transcript message
    errorMsg = "(" + e.RC.ToString() + ") "
    errorMsg += " " + e.Function.ToString() + " "
    errorMsg += e.Message
    ...
End Sub