title: Change voice during phone call android
body: <p>I want to make an android application that allow user change the voice during phone call. For example: You are a man, you can change the voice to a woman or robot when talking over phone. It is like a funny prank.</p>
  
  <p>I work around android's API and google for some days but still have no idea. Some one told is impossible but I see some app on google play can do:
  <a href="https://play.google.com/store/apps/details?id=com.gridmob.android.funnycall" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=com.gridmob.android.funnycall</a>
  So I think there are some ways to do that.</p>
  
  <p>I think about recording and play back by using AudioTracker but I have 2more problem:
  1. I cannot mute the voice from phone call, so the phone only play my sound after processing
  2. record and process will make a long delay (slow-realtime)</p>
  
  <p>Can any one share some solution for this?</p>