title: Android voice activity detection offline
body: <p>I need to detect if there is voice in the environment, and I need to do all the processing in the phone without sending any sound information to a server because of privacy concerns.</p>
  
  <p>I know there is a class in android called SpeechRecognizer <a href="http://developer.android.com/reference/android/speech/SpeechRecognizer.html" rel="nofollow">http://developer.android.com/reference/android/speech/SpeechRecognizer.html</a></p>
  
  <p>But as far as I know, it needs to be connected to a google server (or other server).
  <strong>My question is if there is a way of using this class to detect voice without sending info through internet.</strong></p>
  
  <p>I read a tip from here <a href="http://www.itworld.com/mobile-wireless/327712/use-offline-speech-text-your-android-jelly-bean-device" rel="nofollow">http://www.itworld.com/mobile-wireless/327712/use-offline-speech-text-your-android-jelly-bean-device</a> which says that I could "Download offline speech recognition", but I don't know if this is enough for my needs.</p>
  
  <p>I have some knowledge of signal processing and classification and I think I could develop a voice activity detection by using the Android AudioRecord class, but I would like to know first if SpeechRecognizer permits the detection offline (And how it does) so I could save time.</p>
  
  <p>Thanks in advance for your response.</p>