General American English

[12][4] Standard Canadian English accents may be considered to fall under General American,[13] especially in opposition to the United Kingdom's Received Pronunciation.

[22] William Labov et al.'s 2006 Atlas of North American English put together a scattergram based on the formants of vowel sounds, finding the Midland U.S., Western Pennsylvania, Western U.S., and Canada to be closest to the center of the scattergram, and concluding that they had fewer marked dialectical features than other regional accents of North American English, such as New York City or the Southern U.S.

[12] English-language scholar William A. Kretzschmar Jr. explains in a 2004 article that the term "General American" came to refer to "a presumed most common or 'default' form of American English, especially to be distinguished from marked regional speech of New England or the South" and referring especially to speech associated with the vaguely-defined "Midwest", despite any historical or present evidence supporting this notion.

[33][34] Modern language scholars discredit the original notion of General American as a single unified accent, or a standardized form of English[8][11]—except perhaps as used by television networks and other mass media.

[37] This includes western New England and the area to its immediate west, settled by members of the same dialect community:[38] interior Pennsylvania, Upstate New York, and the adjacent "Midwest" or Great Lakes region.

Linguists have proposed multiple factors contributing to the popularity of a rhotic "General American" class of accents throughout the United States.

[43] Instead, socially-conscious Americans settled upon accents more prestigiously associated with White Anglo-Saxon Protestant communities in the remainder of the country: namely, the West, the Midwest, and the non-coastal Northeast.

Starting in the 1930s, nationwide radio networks adopted non-coastal Northern U.S. rhotic pronunciations for their "General American" standard.

[48] The entertainment industry similarly shifted from a non-rhotic standard to a rhotic one in the late 1940s, after the triumph of the Second World War, with the patriotic incentive for a more wide-ranging and unpretentious "heartland variety" in television and radio.

[89] The following charts present the vowels that converge across these three dialect regions to form an unmarked or generic American English sound system.