Oh, I see your question!
Actually, as I look this up in 191:2.1, and I take the time to read what comes after that question, we can plainly understand that it is Jesus speaking to 10 of the apostles(minus Thomas and Judas Isc) in the upper chamber (where they had the Last Supper), and he asks them more questions which reminded them all of what he had told them about what was going to happen to him at the hands of the Jews.
Yes, all 10 could hear him with their own ears, like you and I have, even though he was in Morontia form - half spirit half human. It doesn't mention any conversation other than his greeting to these men. He was REAL to them.
This was the 9th time (of the 19 appearances) Jesus appeared in this form after his resurrection to believers, family and apostles.
Thanks mama