SpeechRecognizer.AudioStateChanged Event

Definition

Namespace:

System.Speech.Recognition

Assembly:

System.Speech.dll

Package:

System.Speech v9.0.0-rc.2.24473.5

Source:

SpeechRecognizer.cs

Occurs when the state changes in the audio being received by the recognizer.

public:
 event EventHandler<System::Speech::Recognition::AudioStateChangedEventArgs ^> ^ AudioStateChanged;

public event EventHandler<System.Speech.Recognition.AudioStateChangedEventArgs> AudioStateChanged;

member this.AudioStateChanged : EventHandler<System.Speech.Recognition.AudioStateChangedEventArgs> 

Public Custom Event AudioStateChanged As EventHandler(Of AudioStateChangedEventArgs) 

Event Type

EventHandler<AudioStateChangedEventArgs>

Examples

The following example uses a handler for the AudioStateChanged event to write the recognizer's new AudioState to the console each time it changes using a member of the AudioState enumeration.

using System;  
using System.Speech.Recognition;  

namespace SampleRecognition  
{  
  class Program  
  {  
    private static SpeechRecognizer recognizer;  
    public static void Main(string[] args)  
    {  

      // Initialize a shared speech recognition engine.  
      recognizer = new SpeechRecognizer();  

        // Create and load a grammar.  
        Grammar dictation = new DictationGrammar();  
        dictation.Name = "Dictation Grammar";  
        recognizer.LoadGrammar(dictation);  

        // Attach event handlers.  
        recognizer.AudioStateChanged +=  
          new EventHandler<AudioStateChangedEventArgs>(recognizer_AudioStateChanged);  
        recognizer.SpeechRecognized +=  
          new EventHandler<SpeechRecognizedEventArgs>(recognizer_SpeechRecognized);  
        recognizer.StateChanged +=  
          new EventHandler<StateChangedEventArgs>(recognizer_StateChanged);  

        // Keep the console window open.  
        Console.ReadLine();  
      }  

    // Handle the AudioStateChanged event.  
    static void recognizer_AudioStateChanged(object sender, AudioStateChangedEventArgs e)  
    {  
      Console.WriteLine("The new audio state is: " + e.AudioState);  
    }  

    // Handle the SpeechRecognized event.  
    static void recognizer_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)  
    {  
      if (e.Result != null && e.Result.Text != null)  
      {  
        Console.WriteLine();  
        Console.WriteLine("  Recognized text =  {0}", e.Result.Text);  
        Console.WriteLine();  
      }  
      else  
      {  
        Console.WriteLine("  Recognized text not available.");  
      }  

      Console.WriteLine();  
      Console.WriteLine("Done.");  
      Console.WriteLine();  
      Console.WriteLine("Press any key to exit...");  
      Console.ReadKey();  
    }  

    // Put the recognizer into Listening mode.  
    static void recognizer_StateChanged(object sender, StateChangedEventArgs e)  
    {  
      if (e.RecognizerState != RecognizerState.Stopped)  
      {  
        Console.WriteLine();  
        recognizer.EmulateRecognizeAsync("Start listening");  
      }  
    }  
  }  
}  

Remarks

To get the audio state at the time of the event, use the AudioState property of the associated AudioStateChangedEventArgs. To get the current audio state of the input to the recognizer, use the recognizer's AudioState property. For more information about audio state, see the AudioState enumeration.

When you create a delegate for an AudioStateChanged event, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Events and Delegates.

See also

• AudioState
• AudioStateChangedEventArgs
• AudioState