I was listening to Radio NZ yesterday and they had a lady on who had been delving into some sound archives and was presenting some interviews from the 50's and 60's.

Obviously I wasn't here then - and probably few reading this were either - but what struck me was the much clearer diction and pronunciation of both interviewer and interviewee. This led me to posit that the current interpretation of the NZ accent must be relatively new.

I've read quite a number of self-deprecating comments on the accent in press pieces and even after more than 10 years here I still on occasion have more difficulty understanding what someone here said to me (not often but sometimes) than I would a Frenchman speaking French.

Out of pure curiosity, do you think the accent has 'thickened' (for want of a better expression) over 50 years or so and if so, why?