I am developing an Android app with java.
I was curious if it is possible to have an automatic voice message ("Help, I Need an Ambulance") during a phone call. I understand that once you call the phone call method it leaves the application to make a phone call. Is it possible to run a text-to-speech function while the phone call is in progress? That way the phone call can pick up the audio from the text-to-speech function during the phone call.
No, I'm afraid this isn't possible.
There is no audio interface for phone calls, nor any other interface for interacting with telephony. Even something as relatively straight-forward as sending DTMF tones isn't possible without specifically entering them as part of the number to dial, and a basic operation such as hanging up the call is only possible through hidden interfaces.
(While there is AudioManager.STREAM_VOICE_CALL, it can only be used to regulate the in-call volume.)
