title: Android: Check if TTS voice data package is installed
body: <p>I am using Text-To-Speech in my app. It works fine, when the voice data package is installed. However, when no voice data is installed and I call the following method, than no audio is played:</p>
  
  <pre><code>_textToSpeech.speak( text, TextToSpeech.QUEUE_ADD, null );
  </code></pre>
  
  <p>Therefore I want to check if the package is installed to give the user a notification, but I found no way to do this.
  The class "TextToSpeech" provides a method "isLanguageAvailable()". But if voice data is installed or not installed, the result of the method is always the same.</p>
  
  <pre><code>_textToSpeech.isLanguageAvailable(Locale.GERMANY) // result is 1 (LANG_COUNTRY_AVAILABLE)
  
  _textToSpeech.isLanguageAvailable(Locale.GERMAN) // result is 0 (LANG_AVAILABLE)
  </code></pre>
  
  <p>In my android settings the preferred TTS engine is 'Google Text-to-speech'.</p>
  
  <p>Has anyone a clue how to check if TTS voice data is installed?</p>
  
  <p>Thanks..</p>