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SpeechRecognitionEngine.SetInputToWaveFile Method

Configures the SpeechRecognitionEngine object to receive input from a Waveform audio format (.wav) file.

Namespace:  System.Speech.Recognition
Assembly:  System.Speech (in System.Speech.dll)

public void SetInputToWaveFile(
	string path


Type: System.String
The path of the file to use as input.

If the recognizer reaches the end of the input file during a recognition operation, the recognition operation finalizes with the available input. Any subsequent recognition operations can generate an exception, unless you update the input to the recognizer.

The following example performs recognition on the audio in a .wav file and writes the recognized text to the console.

using System;
using System.IO;
using System.Speech.Recognition;
using System.Speech.AudioFormat;

namespace SampleRecognition
  class Program
    static bool completed;

    static void Main(string[] args)

    // Initialize an in-process speech recognition engine.
      using (SpeechRecognitionEngine recognizer =
         new SpeechRecognitionEngine())

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


        // Configure the input to the recognizer.

        // Attach event handlers for the results of recognition.
        recognizer.SpeechRecognized += 
          new EventHandler<SpeechRecognizedEventArgs>(recognizer_SpeechRecognized);
        recognizer.RecognizeCompleted += 
          new EventHandler<RecognizeCompletedEventArgs>(recognizer_RecognizeCompleted);

        // Perform recognition on the entire file.
        Console.WriteLine("Starting asynchronous recognition...");
        completed = false;

        // Keep the console window open.
        while (!completed)

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

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

    // Handle the RecognizeCompleted event.
    static void recognizer_RecognizeCompleted(object sender, RecognizeCompletedEventArgs e)
      if (e.Error != null)
        Console.WriteLine("  Error encountered, {0}: {1}",
        e.Error.GetType().Name, e.Error.Message);
      if (e.Cancelled)
        Console.WriteLine("  Operation cancelled.");
      if (e.InputStreamEnded)
        Console.WriteLine("  End of stream encountered.");
      completed = true;

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.