All the spoken dialog was recorded - e.g., all the dialog that the characters say out loud. All the "thought" dialog - meaning if you look at something and get a description, is not recorded.
The reason for this will be made clear later in the game, when you are controlling four characters at the same time; all of whom can look at anything and have their own unique description for it. We realized very quickly the the sheer amount of VO needed would get very unwieldy very fast, so we opted instead to just record the spoken dialog and nothing else.
