Ms Irwin, an undergraduate with a lust for self-improvement, is taking a class at Queen's College, Charlotte, titled The Sounds of Standard American English. The objective is not so much academic as explicitly practical: to learn how to rein in the Southern drawl and combat the impulse to invent vowel sounds that are not recorded in the written word, as in "pi-uhn" for "pen", or "heyowce" for "house".
"I have a Southern accent and there's nothing wrong with that," Ms Irwin says. "But I know if you sound too Southern when you go for a job interview people think you're not educated."
Her teacher is Charles Hadley, a veteran lecturer in English and phonetics. "We measure students' native accents against what we call general American, the English typically spoken on radio and television, and then we teach them what the proper sounds are," says Dr Hadley, a native Southerner. "We know they'll speak their usual dialect at home, but we hope they can become bilingual so that when they go to a professional situation they will put on their good speech, just as they might put on their Sunday clothes."
Dr Hadley, whose own accent is mellow and genteel but still distinctly Southern, confesses he feels something of a traitor to his people. "We resent the fact we're usually looked upon as underdogs. It's really infuriating to hear people say they must subtract 100 IQ points when they hear a Southern accent, or as someone said to me, 'Can you imagine a nuclear scientist with a Southern accent?'"
And yet he acknowledges that in a country whose chief business, as President Calvin Coolidge once remarked, is business, principle must sometimes be subordinated to pragmatism. "It's very hurtful but it's a fact that if students are going to move north to work they've got to be able to speak with another accent. We hate it but it's essential."
Dr Hadley does not hate the demand that exists for his services. He is thinking of starting evening classes and making a "proper English" instruction tape: "Already I do a lot of private work for banks and industries who send people to me that are on the verge of being promoted but are not going to be promoted - possibly might even be fired - because of the way they speak."
He has done his bit, however, to restore some self-respect to the South. For nearly half a century he has been teaching numerous actors to speak with a Southern accent - Charlton Heston, Faye Dunaway, Nick Nolte and Robert Duvall among them. His first client was Vivien Leigh whom he coached, at the request of her husband Laurence Olivier, for the lead female role in Tennessee Williams' A Streetcar Named Desire.
"In contrast to some of the Americans, Vivien Leigh and every other English actor I ever worked with - Lynn Redgrave was another - have been marvellous in their ability to learn the accent quickly and easily."
The reason why Dr Hadley believes this to be the case might startle British people. "Our accent derives from the Southern part of England. The first settlers down here came over in 1630, landing at Chesapeake Bay in Virginia, and they brought the accent we have today. They were agrarian people, farmers with little education, and that's how the negative view about the South began. That's also why when I'm in Kent, Surrey or Sussex, I always feel right at home. The accent is so familiar."