title: Android TextToSpeech addSpeech() is not working
body: <p>I have an HD Desire phone with android 2.3.</p>
  
  <p>The TTS is working fine and it speaks every text I give. But when I use this either of the lines below to set my own voice for some texts, it simply ignores it and synthesizes the text, just like the line is not written!</p>
  
  <pre><code>tts.addSpeech("salam", "/sdcard/salam.wav");
  tts.addSpeech("shalam", "com.company.appname", R.raw.shalam);
  ...
  tts.speak("salam", TextToSpeech.QUEUE_FLUSH, null);  //&lt;--This isn't playing my voice file.
  tts.speak("shalam", TextToSpeech.QUEUE_FLUSH, null);  //&lt;--Neither is this
  </code></pre>
  
  <p>I am sure of the existence of both files.
  Why is that? Is there any restriction on the sound files? For example on their Frequency, or being mono or stereo?</p>
  
  <p>I already checked the <a href="http://developer.android.com/reference/android/speech/tts/TextToSpeech.html" rel="nofollow">docs</a> and saw nothing related.</p>