Android : How to start speechRecognition inside the JavascriptInerface in android

i have a problem to start the speechRecognition using javascriptInterface. In this case, i have a button in my html page and when i click that button then the speechRecognition should startListening but when i clicked that nothing happen... can anyone explain why?

here the code i'm using :

@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

sr = SpeechRecognizer.createSpeechRecognizer(this);       
sr.setRecognitionListener(new listener());


WebView webView = (WebView) findViewById(R.id.webView1);

initWebView(webView);
webView.addJavascriptInterface(new WebAppInterface(this), "Android");

webView.loadUrl("file:///android_asset/index.html");

}

my javascriptInterface class

class WebAppInterface{
 Context mContext;
 WebAppInterface(Context c) {
     mContext = c;
 }


 @JavascriptInterface
 public void startListening(){
      Intent intent = new    Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);        
      intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
      intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, Locale.getDefault());
      intent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE,"com.domain.package");
      sr.startListening(intent);
 }

}