Variant pronunciations of words are more common than variant spellings. And just as dictionaries try to reflect accepted spellings, so also do they give common pronunciations. They seldom, of course, catch local accents, twangs, intonations or cadences.
Bostick, Charles W.
Word Ways: Vol. 10
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol10/iss1/10