WP8中的SpeechRecognizerUI导致高崩溃次数

我一直在开发一个笔记应用程序，我已经包含了SpeechRecognizerUI，这样用户就可以直接从语音中记笔记。把这个应用程序放到商店后，我注意到崩溃次数非常高。我也收到了一些用户的投诉，说这个应用程序随机崩溃。我试了很多次，但没有崩溃。所以我从开发中心网站导出了堆栈跟踪。

所有的崩溃都与SpeechRecognizerUI有关。。有人知道怎么解决这个问题吗？

这是我在页面中使用的代码：-

SpeechRecognizerUI recoWithUI;  //Speech to text
SpeechSynthesizer synth;    //Text to speech
public NoteView()
{
    InitializeComponent();
    recoWithUI = new SpeechRecognizerUI();
    synth = new SpeechSynthesizer();
    recoWithUI.Recognizer.AudioProblemOccurred += Recognizer_AudioProblemOccurred;
}
private async void RecordButton_Click(object sender, EventArgs e)
{
    try
    {
        SpeechRecognitionUIResult recoResult = await recoWithUI.RecognizeWithUIAsync();
        if (NoteBox.Text == "")
            NoteBox.Text = recoResult.RecognitionResult.Text;
        else
            NoteBox.Text = NoteBox.Text + " " + recoResult.RecognitionResult.Text;
    }
    catch (Exception ex)
    {
    }
}
async void Recognizer_AudioProblemOccurred(SpeechRecognizer sender, SpeechAudioProblemOccurredEventArgs args)
{
    if (args.Problem == SpeechRecognitionAudioProblem.NoSignal)
        await synth.SpeakTextAsync("I can't hear you");
    else if (args.Problem == SpeechRecognitionAudioProblem.TooFast)
        await synth.SpeakTextAsync("That's too fast");
    else if (args.Problem == SpeechRecognitionAudioProblem.TooLoud)
        await synth.SpeakTextAsync("That's too loud.");
    else if (args.Problem == SpeechRecognitionAudioProblem.TooNoisy)
        await synth.SpeakTextAsync("There's too much noise");
    else if (args.Problem == SpeechRecognitionAudioProblem.TooQuiet)
        await synth.SpeakTextAsync("Try speaking louder");
    else if (args.Problem == SpeechRecognitionAudioProblem.TooSlow)
        await synth.SpeakTextAsync("Try speaking faster");
}

if (recoResult.RecognitionResult != null)
{
    //...
}