When Jack uses the intercom, whispers can be heard which decode as:
"Has she tried to talk to him / Shall we talk to him"
"Look on "
"Has he answered / His head is hurt"
"Don't / Won't talk"
"We're not sure if he knows that much / We're not sure if we'll find out much"
"That's what I was thinking"
"Let him go free"
"It's not easy keeping something that secret / sacred"
"What are you gonna do / Go on and do it"
Christian Shephard's voice "Let it go Jack "
"Now I can tell what you're doing "
"Bring it back to her"