The short answer is "it depends".
Tali's mobile app uses your phone's settings and so what it is able to hear depends on your phone's settings, along with the application you may be using to speak with your patient on your phone.
Some phones automatically filter out audio that is played through their own speakers from their own mic, to avoid echoing.
That being said, we have heard that in some cases, Tali does hear the conversation and that the echoing doesn't happen either.
Due to this, we suggest all our users try mock conversations with a friend as a test patient to confirm what Tali hears while they use Tali through our mobile app.