Android: Transmit sound to somebody during a call?

I've looked up and down the SDK for this, but I can't find anything. I'm wondering if there's a way to transmit a sound, such as a WAV or OGG, during a call such 开发者_运维问答that the person on the other end can hear it. (This sound should be heard in addition to, not in place of, the normal voice transmission.) Is there a possibility I may have overlooked?

No, sorry -- Android applications have no access to the in-call audio stream. Now, if the user has the phone in speakerphone mode, I think noises you play on the speaker might be picked up by the microphone, but of course the quality is so-so.