can speech recognizer take input from incoming call voice (Speaker)?

问题

1. During a phone call application listens to the incoming phone call
   i.e incoming voice from speaker not the mic.
2. Converts the caller's(the person who has make a call to you) voice to text.
3. Finally display that converted text into the text view.
4. It does all this conversion while the phone call is happening.

来源：https://stackoverflow.com/questions/42521023/can-speech-recognizer-take-input-from-incoming-call-voice-speaker