It is rather rare to hear a speaker pronounce vowels like this, so I would like to know where it comes from. I live in North America, so my only experience is with American English.
Most notably, I have heard /ɑ/ in "got" pronounced as /æ/. As well, "no" as "nɛ". And come to think of it, "actually" which should use /æ/ is being pronounced as /ɛ/.
A more common occurrence may be the /e/ in "okay" substituted for /ə/, /ɪ/, or /i/.
I have found a couple of examples from this video, such as "end" as [ɪ]nd. It's not necessary to watch but may help. It's not the prominent accent that I've heard, as in the first example.
But my question is where did this begin, and where in the US does it occur most?