SpeechRecognitionEngine.SpeechDetected Event

Article
10/07/2009

Event raised by recognition engine when speech is detected.

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

Syntax

'Declaration

Example

The example below shows the subscription of an anonymous method as a handler for SpeechDetected. The handler displays the current state of the recognition engine, including the audio position of the speech that generated the event (Utils.DisplaySpeechDetected).

_recognizer.SpeechDetected +=
    delegate(object sender, SpeechDetectedEventArgs eventArgs) {
//Clear previous recognition information
_audioDeviceStatusLabel.Enabled = true;
_audioDeviceStatusLabel.Visible = true;
Utils.DisplayAudioInputFormat(_audioStateLabel, _recognizer);
Utils.DisplaySpeechDetected(_speechDetectedLabel, eventArgs.AudioPosition);

    };

Remarks

Recognition engines have algorithms able to distinguish between background sound, random noise, and speech.

When the algorithm is satisified, a SpeechDetected is raised.

SpeechDetected events are always be followed by one or more SpeechHypothesized events, and finally by either a SpeechRecognized or SpeechRecognitionRejected event when the recognizer has finished processing the speech.

The position of the audio input to trigger a SpeechDetected event can be obtained by the SpeechDetected handler through the AudioPosition property of the SpeechDetectedEventArgs object passed to the handler.

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

SpeechRecognitionEngine.SpeechDetected Event

Syntax

Example

Remarks

Platforms

Development Platforms

Target Platforms

See Also

Reference

Additional resources