I find it a bit confusing, when the author tries to write it as an accent... As in, spelling it like he'd be pronouncing it.
I've written characters with accents, and I just give a brief intro that they're from a certain place, or have the other characters react to their accent, so it's apparent---to the reader---that they will be speaking with this accent... Some of them are from another country, so they will say a few typical words from their particular area, as well.