Playing An Pre-recorded Audio File To Somebody Over A Call

I understand that even though the AudioManager.STREAM_VOICE_CALL is available in the SDK for android, it is not actually been used to play a pre-recorded audio file, or atleast tha

Solution 1:

My Question is this, if this is truly the way it is, how is prankdial accomplishing this?

It is impossible. Android applications do not have access to the in-call audio stream. AudioManager.STREAM_VOICE_CALL is for volume control.