That's super easy already. You can make the phone act as a USB sound card, or you can use PulseAudio's network transparency (see https://puri.sm/posts/speak-to-

That's super easy already. You can make the phone act as a USB sound card, or you can use PulseAudio's network transparency (see https://puri.sm/posts/speak-to-me/ https://puri.sm/posts/speak-to-me/), or you can broadcast an RTP stream, or you can use Bluetooth audio...