[Freeswitch-users] 3-party call where 2 people should not hear each other

I'm looking at a problem for a potential client. They want to do three party PSTN calls where all audio is NOT routed to all parties. Two parties (A and B) are in the same room but are using separate handsets rather then a speaker phone. The third party (C) is at a remote location. C should hear audio from A and B A and B should both hear audio from C but not from one another. Since they are both in the same room hearing the audio from one another in the handset as well is just distracting. My client has previously experimented with Twilio and figured out that their API does provide a solution.