How to play sound on the phone for a remote interlocutor programmatically?

Question

Android

Is there a way to play back a previously recorded sound to the interlocutor? Like a standard mp3 player, but to broadcast sound to the transmission path, and not to the speaker. There are many programs for recording conversations, but for playback in the "backward direction"? So far, the easiest way seems to be to play the recording on one phone, and bring the second phone close to the first, but the sound quality will be lost. I'm sure there must be some ready-made software solutions.

Answer 1

android.stackexchange.com/questions/9992/how-can-i...

Answer 2

I looked for more materials, I had to look for autoresponders. It looks like it's bad. Manufacturers often block the ability to both read and write to the line from the OS.

protabletpc.ru/programs/prilozhenie-avtootvetchik-...
Despite all the advantages of Android, such a valuable thing as an autoresponder is almost impossible to implement normally.
rVoix - for happy owners of HTC This application is almost the only one that allows you to get a full-fledged answering machine on your Android device. You need to be the proud owner of an HTC device powered by a Qualcomm msm72xx/msm76xx processor. This is the only series of products where there is hardware support for recording phone calls and transmitting audio to the line. Root is required to function. Download the program from the Play Store at the link... Please note that operation is not guaranteed on other HTC models.

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add. You can make your own "phone" and programmatically control sound flows in all directions. In some cases it may come in handy. Examples of ready-made solutions:
vrtp.ru/index.php?showtopic=20314&st=450
vrtp.ru/uploads/post-55-1360685482.jpg
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forum.cxem.net/index.php?/topic/99558-%D0 %BF%D0%BE...
phreakerclub.com/forum/showthread.php?t=989
avrproject.ru/publ/kak_podkljuchit/gsm_modul_sim90...