Kinect语音识别异常

Question

如何将Microsoft.Speech.Recognition与默认音频源一起使用。我使用recognizer.SetInputToDefaultAudioDevice()但是出现了这个错误：

  

InvalidOperationExeption：类型的未处理异常   Microsoft.Speech.dll

中发生'System.InvalidOperationException'

这是我的代码

using Microsoft.Speech.Recognition;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            StartRecognition();
        }

        private SpeechRecognitionEngine recognizer = new SpeechRecognitionEngine();

        private void StartRecognition()
        {
            recognizer.SetInputToDefaultAudioDevice();       //Here is my problem
            recognizer.RecognizeAsync(RecognizeMode.Single);
        }
    }
}