Yinz be sure to check it aht! A radio interview with Scott Kiesling on the origins and evolving nature of Pittsburghese.
A great way to test if someone may be from Pittsburgh based on pronunciation, said Kiesling, is to have them say the phrase “Knox’s Pierogi House.”
“So you’ve got to get the ‘aw’ in Knox and the ‘oh’ in pierogi and the ‘ah’ in house,” Kiesling said.
This illustrates a vowel shift called monophthongization. It’s when vowels merge and make words a little shorter. It’s evident in how the “ow” in “downtown” changes to “ah” in the Pittsburgh pronunciation, “dahntahn.” Read and listen more (and be sure to listen to Pittsburgh Dad give directions--it's hilarious!) at http://wesa.fm/post/redd-your-pittsburghese-deep-dive-how-yinz-talk