In a recent column, Marilyn Vos Savant (a columnist with an allegedly record-setting IQ) wrote:
I’ve retained 99+ percent of my Midwestern ‘accent,’ which sounds like no accent at all because nearly all the words are pronounced according to dictionary standards.
A reader understandably objected to this (flagrantly wrong) statement, and Savant clarified in a later column:
I understand what you’re expressing, but Midwestern speech is widely considered to be closest to the way English is spoken in this country (i.e. without a regional accent) because, as I mentioned, nearly all the words are pronounced according to dictionary standards.
In a word, no. American “dictionary standard” (which honestly, isn’t really a thing to begin with) usually reflects “General American English” (GenAm), a rather hypothetical and amorphous “standard.” You can, admittedly, find accents quite close to “classic” GenAm in the Midwest, in the Western section of what William Labov calls the North Midland*. This constitutes a narrow band roughly encompassing Northern Missouri, Southern Iowa, Southern South Dakota, most of Nebraska, and northern Kansas.
But “midwestern English” encompasses many unique dialects, not all of which sound like the folks who read you the morning news. Beyond the GenAmish accent just referenced, one finds the Great Lakes (Northern Cities Vowel Shift-influenced) accent, the German/Scandinavian-influenced accents of Northern Minnesota and North Dakota, and the “South Midland” accent found in Missouri, Illinois and Indiana. That’s a broad (and non-exhaustive) list of categories, excluding the sub-dialects and urban dialect islands one finds throughout the region.
Speaking of which, it is worth noting that Vos Savant hails from St. Louis, a city with an isolated local accent located outside Labov’s Western-North Midland region. It’s possible her accent is a “mild” or “modified” version of St. Louisian, falling within the range of General American English. But one can such accents in many US regions days (just note the distribution of “unmarked” speakers on Labov’s map). GenAm isn’t exclusively a “midwestern thing” anymore.
There is almost certainly some truth to the notion that General American English has Midwestern origins. The term is associated with the dialect-levelling that occurred during the 20th Century. Since this entailed “Southern” accents becoming less “Southern,” “Northern” accents becoming less “Northern,” and “Eastern” accents becoming less “Eastern” (goodbye, “toidy-toid street!”), it’s not surprising that the English spoken smack dab in the nation’s middle might be described as kind of de facto standard.
At the end of the day, though, I’m less bothered by Vos Savant’s suggestion that her accent is “standard English” so much as I’m bothered her narrow definition of what constitutes a “midwestern accent.” Just as attempts to describe Midwestern monoculture ignore the the region’s unique individual parts, speaking of a supposedly monolithic “Midwestern English” as if it were the way “normal” Americans talk ignores the area’s wonderful linguistic diversity.
*I’m basing this on the fact that this area generally avoids overtly Southern or Northern features, and also largely eschews features of the Northern Cities Vowel Shift.