Map Your Voice. Follow the link and click on a red dot on the map to play a clip of a person in that location reading a short children's text. Click a green dot to hear six words "controversy, garage, neither, scone, schedule, attitude" spoken by people, often not natives of the area.
How did your immigrant ancestors pronunciation change? From my own experience pronunciation can shift fairly quickly to that of the community in which you are immersed. When I moved to Colorado in the 70s I soon found myself saying zee rather than zed, and equally quickly changed back on return.
You can also contribute your own recording.
Map your voice is part of the British Library's Evolving English exhibit online.