> As for your Northern Illinois accent. Chicago? Northern Cities

Vowel Shift? Do you hear 'chopsticks' when someone not of your
dialect says 'ChapStix' (ChapStix is the brand name of a lip balm).

I'd be grateful for a short explanation of what the Vowel Shift is
and where the Vowel Shift Belt is situated. Thanks.

Juozas Rimas