private KeywordRecognizer recognizer;

private void Start()
{
    if (keywords != null)
    {
        recognizer = new KeywordRecognizer(keywords, confidence);
        recognizer.OnPhraseRecognized += Recognizer_OnPhraseRecognized;
        recognizer.Start();
    }
}

private void OnApplicationQuit()
{
    if (recognizer != null && recognizer.IsRunning)
    {
        recognizer.Stop();
    }
}

private void Recognizer_OnPhraseRecognized(PhraseRecognizedEventArgs args)
{
    word = args.text;
    results.text = "You said: <b>" + word + "</b>";
}