Untangling the talk

What humans say to each other is perplexing at the best of times. But what if all you have is sight, no sound? Deaf people 'see' language through signing and lip-reading -- with surprising brain scan results. Forensic linguists often only have sound, no sight -- working with grisly sound recordings from murder scenes and covert criminal deals, to sleuth for suspects. Tune in to untangle some tricky talk.