What's so sexy about Bond's accent?

"It means they're independent, they have means and a job that's interesting."

For Bond: check, check and check.

Daniel Craig speaks in Received Pronunciation, or RP, known as the "Queen's English." It's just one of many distinct British dialects, but it's the best known around the world and often linked to the south England elite.

"We're one of the few countries in the world that has an acrolect -- an accent of the elite," Shepherd said.

Around the Industrial Revolution, as people became more socially mobile, they strove to emulate the accent heard around London.

Shepherd said when you listen to Craig, he presents as well-spoken and well-educated. He's soft on his consonants.

His voice is familiar to an older audience, but "Daniel Craig is a kind of modern RP speaker, which is why he's received so well," Shepherd said. "He's relatable. People under 50 say, 'I like his sound. It's not too posh, not too distant from us.'"

Most of Shepherd's work on the film, though, was with French actress Lea Seydoux, who plays the latest "Bond girl." Her accent has to be an effortless match for Bond's, while still sounding foreign.

"We're working on an RP model, but try to keep her sounding French," Shepherd said. "If you have an American accent and a British accent, those will serve you very well as an actor."

But what about the rest of us?

Beyond just where someone is from, Shepherd said, you can tell a lot about a person by their accent.

"What I think is really interesting about accents, mainly, is they kind of assign us immediately to a tribe, but they are this ever-changing social history as we're walking about -- what we've been through as well as what we want to get to," said Shepherd.

"I personally change my accent all the time. Sometimes I do it just to mess with waiters by ordering every course in a different accent."

As part of a recent marketing campaign, British Airways conducted a survey about accents that included interviews with of 1,000 Brits and 1,000 Americans.

Americans interviewed about U.K. accents said the Glaswegian accent -- think Craig Ferguson or James McAvoy -- was the sexiest. The most intelligent accent was Geordie -- think Sting.

Americans said Sean Connery, who played 007 six times, has the best British accent of all time. His manner of speaking drifts away from the elite RP manner of speaking, Shepherd said.

"What Sean Connery has is just the voice he uses in all of his movies," said Shepherd. "It doesn't really change."

The best U.S. accent of all time, according to Brits? Morgan Freeman's soft Tennessee tones.

"Come on! It's Morgan Freeman," said Shepherd. "He's divine. I'd listen to him read my shopping list."

The sexiest accent overall, poll participants said, belonged to Italians. In multiple scientific studies on accents, Irish and French always rank among the sexiest, Shepherd said.

"Irish basically has a really beautiful musicality," said Shepherd. "They start at the top and go all the way down to the bottom. The other thing they do that adds to the beauty of it is they're soft on the consonants, like Ds and Ts. If (the Irish language) were a person, it'd be very sensitive and spiritual."

Still, no accent is forever. They evolve naturally, even within a person's lifetime. Sometimes, people seek out training to change them.

"I get a lot of calls from people who want accent softening, who say, 'I want to sound like the queen,'" Shepherd said.

She tries to convince them otherwise, to go with something warmer.

"I hope my generation will rebel against that a bit," she said. "Unless you're over 60, that sounds weird. Generally speaking, you don't want to sound like the posh guy who doesn't care about the poor. It's not as attractive as it once was.

"But outside the U.K.," she admits, "it becomes really gorgeous."