Despite what old SF movies claim, computers are going to be able to see and understand human emotional affects just fine.
By doing gait analysis, watching for facial blood flow using IR cameras, using high frame rate video with very advanced facial recognition software that is looking for micro expressions, eye motion, and pupil changes, and by analyzing vocalizations for stress, it's probable that eventually the machines are going to be better at recognizing a human's emotional state than most humans can.
And stuff like spoken sarcasm and irony, will be transparently obvious.
And, of course, that the machine can see this, means that it can be serialized, recorded, and transmitted. It would be just as much part of a transcription of a conversation as the spoken words are.
By no means will this be a magic "lie detector", but it will probably be a bit better than a trained human's skill at it.