Tina Turner and Madonna have been doing it for years; now add wacky chanteuse Britney Spears to the list. Two weeks ago, in yet another confrontation with paparazzi, she suddenly started speaking (screaming, actually) like My Fair Lady’s Eliza Doolittle.

Perhaps it’s the influence of her latest beau, a British paparazzo named Adnan Ghalib, who tells reporters Spears just thinks talking like the Geico gecko is cute.

But possibly the girl is on to something: Putting on an accent could be a pragmatic move — as with Democratic presidential candidates Hillary Clinton and Barack Obama, two non-Southerners drawlin’ their way through the South on the campaign trail.

Faking an accent can even be seen as cool, not unauthentic or un-American. Cue Justin Timberlake, the ultimate Disney white boy, talking like a hip-hop dude in his music and performances — and getting away with it.

“To align himself with artists like Timbaland to acquire credibility, that’s a big breakthrough for a former boy-bander who used to wear white parachute pants,” says Us Weekly editor Janice Min.

Communication experts say some accent changes are normal “linguistic accommodation.” Madonna, for instance, started talking like a Brit when she was hanging out with English actor Rupert Everett, and it intensified after she moved to London and married Scottish director Guy Ritchie. Many foreigners who live in the USA for years often lose their accents, at least partly; Bono, for instance, doesn’t sound quite as Irish as he did when U2 first appeared in the USA.

“There is nothing unnatural about people making some adjustments in the direction of the locals when they move to a very different accent region,” says Jack Chambers, a University of Toronto linguistics professor. “So Madonna, living in England, alters her low vowel in rather so that it comes out as rahther. Most of her accent is middle-class Michigander except for these few accommodations.”

Some sudden accent changes are the relatively rare result of psychiatric disorders or physical brain trauma; there’s even a name for it — foreign accent syndrome.— but typically the patient, after a stroke, could speak in a Scandinavian or Eastern-European accent, not a British one, says Jack Ryalls, professor of communicative disorders at University of Central Florida in Orlando, who studies the syndrome.

But possibly at work here is the mystifying American notion that a British accent connotes more intelligence and culture than a standard American accent — even the working-class accents that might make the British themselves try to sound like Russell Crowe.

“Somehow a British accent conveys some sort of higher status,” so adopting one can make the insecure feel better, especially performers, Min says.

“They change their hair, they change their shoes, and if you’re a celebrity of a certain type, you might change the way you speak.”

Carmen Fought, a linguistics professor at Pitzer College in Claremont, Calif., says Americans’ bias for Brit-speak is illustrated in the hilarious/pathetic scene in the British film Love Actually, in which a working-class English schlump in a Milwaukee bar attracts a gaggle of American sexpots.

“He’s got a lower socio-economic accent, the equivalent of our ‘redneck’ accent, but these women drape themselves all over him because of the way he talks — they think he’s sexy,” she hoots. (Or, as the character, Colin, boasts, “Over there, I’m Prince William — without the weird family.”)

Why the inferiority complex? It dates back to Colonial days, when everything from the mother country was esteemed, except for England’s aristocrats and anti-democratic class system.

“But people yearn for social hierarchy, England provided the prestige style at the time, and it was World War II that brought (American) self-pride,” says Sam Chwat, director of New York Speech Improvement Services, which coaches hundreds of people, including famous actors, on how to acquire or eliminate accents.

Still, aside from PBS, Britain’s posh tones have not yet invaded American television, though scores of British (and Australian) actors have, while sounding flawlessly American. Hugh Laurie of Fox’s House is so good at Yank-speak that many Americans are surprised to hear what he really sounds like on late-night talk shows.

Some foreign-born performers work to banish their accents, while others either can’t or don’t care: South African-born Charlize Theron watched American TV to bury her Afrikaans accent, but actor-turned-California Gov. Arnold Schwarzenegger still sounds Austrian after decades in the country.

Putting on the Ritz via an accent can be tricky. English singer Joss Stone, 20, was slammed in the British media for using an American accent at home after making a record in the USA. Even Madonna, whose entire persona is about reinvention and whatever’s next, has been mocked back home for her faux accent. “It’s been viewed as treachery, as giving up something she should have been proud of,” says Chwat.

It’s even more risky when whites try to imitate black hip-hop speaking patterns. “It’s a complicated dance between middle-class whites and black street culture, but for those looking for a bit of edge, this is a place you can go,” Min says.

But not Clinton or Obama. She’s from Illinois, with a flat Midwestern accent, and he’s from Hawaii, with a regionally neutral accent — and both were jeered by online bloggers for speaking “southern” in the South. In one speech, Clinton recited the lyrics to an African-American spiritual in cadences apparently meant to approximate a black church choir. Video of her awkward performance on YouTube inspired withering online derision; “pandering idiot” is one of the milder comments.

As for the continuing value of a British accent: This year’s Oscar nominations, announced last week, reinforced the trend of recent years that has British-accented actors as leading contenders for the prize.