Thats the CVR (Cockpit voice recorder) 30 mins is the minimum recording, CAA, FAA, NTSB, AAIB all recomend 2 hours recording.
FDR ( Flight data recorder ) will record all other parameters...ie flying controls, settings , in fact most things that are selectable on aircraft.
35 years aircraft engineer....but no 'expert' like all these oafs on TV
Likewise I was an aircraft engineer and I agree there's so much crap spoken from 'experts'.
When you hear something on tv that you know is rubbish, it makes you wonder about other things being spoken about subjects that you're a layman in.