After Googleing and looking through StackOverflow, I haven't found a suitable solution to "inject audio from an iPhone app into an ongoing phone conversation."
As an iPhone app dev newbie, I found Intercepting phone call - iPhone (correct method to hook in CoreTelephony), but I don't want to do ant jailbreaking. I want my iPhone app to insert pre-recorded phrases and noise effects into an ongoing phone conversation.
Can anyone tell me where I would start with that? Any hints, links or just some "general direction" advice would be much appreciated.