When I spoke of people talking through what the musicians were doing, i was referring to clubs and other small venues, often where drink was served. These are now quiet in my experience, except for some pub venues where musicians and listeners have to put up with those who are only there for the booze. Manchester's Matt and Phred's is an example - I never went back! Jazz concerts were always as you describe - I being too young and far away to have experienced an American JATP event.