SpeechRecognitionEngine.SpeechRecognitionRejected Event

The event raised when the recognition engine detects speech, but can only return candidate phrases with low confidence levels.

Namespace: Microsoft.Speech.Recognition
Assembly: Microsoft.Speech (in microsoft.speech.dll)

Syntax






Example

The example below shows the subscription of an anonymous method as a handler for SpeechRecognitionRejected, which in turn calls a display function (DisplayResult)to return to the user interface the best candidate and the list of alternates generated.

_recognizer.SpeechRecognitionRejected +=
    delegate(object sender, SpeechRecognitionRejectedEventArgs eventArgs) {
Utils.DisplayAudioInputFormat(_audioStateLabel, _recognizer);
DisplayResult(eventArgs);
    };

// Displays the semantics, rules, and alternates of the result.
private void DisplayResult(EventArgs eventArgs) {

    //Make sure We handle different event types we support
     RecognitionResult result=null;
    if (null !=(eventArgs as RecognitionEventArgs)) {
result = (eventArgs as RecognitionEventArgs).Result;
    }else if (null !=(eventArgs as EmulateRecognizeCompletedEventArgs)) {
result = (eventArgs as EmulateRecognizeCompletedEventArgs).Result;
    }

    // In all cases, clear results, semantic XML, semantics tree, and alternates.
    _recognitionSmlBrowser.Navigate("about:blank");
    _semanticsTreeView.Nodes.Clear();
    //            _candidateList.Items.Clear();
    _candidateList.DataSource = null;
    _candidateList.DisplayMember = null;
    _phraseInfoLabel.Text = "";
    _bestCandidateTextBox.Text = "";

    if (result != null) {
//If eventArgs not null repopulate displays
//Obtain result from RecognitionEventArg passed in.


//Set Text color on the basis of the event type passed in.

switch (eventArgs.GetType().ToString()) {

    case "Microsoft.Speech.Recognition.SpeechHypothesizedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.Black;
        _bestCandidateTextBox.Text = result.Text;
        _phraseInfoLabel.Text = null;
        break;
    case "Microsoft.Speech.Recognition.SpeechRecognitionRejectedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.OrangeRed;
        _bestCandidateTextBox.Text = "Unable to Recognize Input";
        _phraseInfoLabel.Text = String.Format("Rejected Phrase Information\n");
        Utils.DisplayBasicPhraseInfo(_phraseInfoLabel, result);
        Utils.DisplaySemanticsSML(_recognitionSmlBrowser, result);
        Utils.DisplaySemanticsTreeView(_semanticsTreeView, result.Semantics);
        break;
    case "Microsoft.Speech.Recognition.SpeechRecognizedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.Green;
        _bestCandidateTextBox.Text = result.Text;
        _phraseInfoLabel.Text = String.Format("Recognized Phrase Information\n");
        Utils.DisplayBasicPhraseInfo(_phraseInfoLabel, result);
        Utils.DisplaySemanticsSML(_recognitionSmlBrowser, result);
        Utils.DisplaySemanticsTreeView(_semanticsTreeView, result.Semantics);
        break;
    case "Microsoft.Speech.Recognition.EmulateRecognizeCompletedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.Green;
        _bestCandidateTextBox.Text = result.Text;
        _phraseInfoLabel.Text = String.Format("Recognized Phrase Information\n");
        Utils.DisplayBasicPhraseInfo(_phraseInfoLabel, result);
        Utils.DisplaySemanticsSML(_recognitionSmlBrowser, result);
        Utils.DisplaySemanticsTreeView(_semanticsTreeView, result.Semantics);
        break;
    default:
        _bestCandidateTextBox.ForeColor = Color.Black;
        break;
}

Utils.DisplayDataOnListBox(_candidateList, result.Alternates, "Text");

    }
}

Remarks

Handlers of SpeechRecognitionRejected events can obtain the best possible candidate phrase, as well as a list of up to MaxAlternates phrases with lower confidence levels through an instance of the RecognitionResult object returned by the Result property of the SpeechRecognitionRejectedEventArgs object passed to the handler. (SpeechRecognitionRejectedEventArgs is derived from[SpeechRecognitionEventArgs)](https://msdn.microsoft.com/en-us/library/microsoft.speech.recognition.speechrecognitioneventargs)(v=office.13))).

The confidence level cut off for recognition is an arbitrary feature of any particular recognition engine and is not settable by applications.

Platforms

Development Platforms

Windows XP Professional with Service Pack 2 (SP2), Windows Server 2003, Windows Vista Ultimate Edition, Windows Vista Business Edition, Windows Vista Enterprise Edition

Target Platforms

See Also

Reference

SpeechRecognitionEngine Class
SpeechRecognitionEngine Members
Microsoft.Speech.Recognition Namespace
SpeechRecognitionEngine Class
RecognitionEventArgs Class
SpeechRecognitionRejectedEventArgs
SpeechRecognitionEngine.SpeechDetected Event
SpeechRecognitionEngine.SpeechHypothesized Event
SpeechRecognized