It was Janice Nicholls, and the show was 'Thank Your Lucky Stars'. although a lot of people think it was 'Juke Box Jury'.
Back in the early days of TV, a member of the public getting noticed like this was a new phenomenon. The advent of TV meant that people could actually hsee and hear people from other areas, and Janice's broad Black Country accent was so novel and unusual, that ther pronunciation passed into national usage.
These days, everyone knows how everyone else speaks, so the notion of someone with broad accent would be no cause for comment whatsoever.