General American is a national accent of American English based on speech patterns common in the Midwest of the United States and those used by many American network television broadcasters. It is also sometimes called Standard Midwestern. The General American accent or dialect is not thought of as a linguistic standard in the sense that Received Pronunciation (RP) is the standard, prestige variant in England and British society historically, but its speakers are perceived as "accentless" by most Americans. The idea of a uniform media American accent has declined in popularity since the late 1960s.
Full vowels:
Monophthongs
Checked
Free
Front
Central
Back
Front
Central
rhotacized
Back
Close
Close-mid
Open-mid
Open
//: bid
//: good
//: bed
//: bud
//: bad
//: bead
//: booed
//: bayed
//: bode
//: bird
// or //: bought
//: pod, father
Note: the vowels // and // are diphthongal for many American speakers, so the transcriptions // and // are also often used.
Diphthongs
Closing
Rhotacized
to //
to //
Starting close
Starting mid
Starting open
//: boy
//: buy
//: cow
//: beer
//: boor (often replaced by //, sometimes by // in American English)