From the walkthrough:
Go outside the hospital to call Moretti about radio transmissions. Return inside and you get a message from Moretti. Read the message, and then scroll down in the audio clips to see the radio message.
Return to cell three. Play the radio transmission for the patient.
I don't still have this game on my computer so I can't check it, but I can recall I didn't see it there the first time I played, because I expected it to be with the text messages.